December
2013
Updated: 1 December 2013
Welcome to the night skies of Spring,
featuring Taurus, Orion, Canis Major and Jupiter
Explanatory Notes:
Rise and set times are given for the theoretical horizon, which is a flat horizon all the
way round the compass, with no mountains, hills, trees or buildings to obscure the view. Observers will have to make allowance for their own actual
horizon.
Transient phenomena are provided for the current month and the next. In the list of geocentric events, the nearer object is given first.
When a planet is referred to as ‘stationary’, it means that its movement across the stellar background appears to have ceased, not that
the planet itself has stopped. With inferior planets (those inside the Earth’s orbit, Mercury and Venus), this is caused by the planet heading either directly
towards or directly away from the Earth. With superior planets (Mars out to Pluto), this phenomenon is caused by the planet either beginning or ending its
retrograde loop due to the Earth’s overtaking it.
Apogee and perigee: Maximum and minimum distances of the Moon or artificial satellite from the Earth.
Aphelion and perihelion: Maximum and minimum distances of a planet, asteroid or comet from the Sun.
A handspan at arm's length covers an angle of approximately 20 degrees.
mv = visual magnitude or brightness. Magnitude 1 stars are very bright, magnitude 2 less so, and
magnitude 6 stars are so faint that the unaided eye can only just detect them under good, dark conditions. Binoculars will allow us to see down to magnitude
8, and the Observatory telescope can reach visual magnitude 15 or 19 photographically. The world's biggest telescopes have detected stars and galaxies as faint as
magnitude 30. The sixteen very brightest stars are assigned magnitudes of 0 or even -1. The brightest star, Sirius, has a magnitude of -1.44. Jupiter can reach -2.4, and
Venus can be more than 6 times brighter at magnitude -4.7, bright enough to cast shadows. The Full Moon can reach magnitude -12 and the Sun magnitude -26.5. Each
magnitude step is 2.51 times brighter or fainter than the next one, i.e. a magnitude 3.0 star is 2.51 times brighter than a magnitude 4.0. Magnitude 1.0
stars are exactly 100 times brighter than magnitude 6.0 (5 steps each of 2.51 times, 2.51x2.51x2.51x2.51x2.51 = 2.515 = 100).
Solar System
Sun:
The Sun begins the month in the non-zodiacal constellation of Ophiuchus, the Serpent Bearer. It leaves Ophiuchus and passes into Sagittarius, the Archer on December 18.
Moon Phases:
Lunations this month: #1123 1124
New Moon:
December
3
10:23 hrs
diameter = 33.0'
First Quarter:
December
10
01:12 hrs diameter =
31.7'
Full Moon:
December
17
19:29 hrs diameter =
29.6'
Last Quarter:
December
25 23:49 hrs diameter =
30.5'
New Moon:
January 1 21:15 hrs
diameter = 33.5'
First Quarter: January 8
13:40 hrs
diameter = 31.1'
Full Moon:
January 16
14:53 hrs
diameter = 29.4'
Last Quarter:
January 24
15:20 hrs
diameter = 31.2'
New Moon: January 31
07:39 hrs diameter =
33.4'
Lunar Orbital Elements:
December
01: Moon at
ascending node at
02:58 hrs, diameter = 32.2'
December
04:
Moon at perigee (360 063 km) at 20:02 hrs, diameter = 33.2'
December
13:
Moon at descending node at 20:13 hrs, diameter = 30.4'
December
20: Moon at
apogee (406 276 km) at 09:57 hrs, diameter = 29.5'
December
28: Moon at
ascending node at
10:17 hrs, diameter = 31.7'
January
2: Moon at perigee
(356 945 km) at 06:48 hrs, diameter = 33.5'
January
9:
Moon at descending node at 21:29 hrs, diameter = 30.6'
January
16: Moon at
apogee (406 531 km) at 11:43 hrs, diameter = 29.4'
January
24: Moon at ascending node at
12:52 hrs, diameter = 31.1'
January 30:
Moon at perigee (357 098 km) at 19:39 hrs, diameter = 33.5'
Moon at 8 days after New, as on December 11
Moon at 9 days after New, as on December 12
The two photographs above show the Mare Imbrium area in the Moon's northern hemisphere. They were taken a day apart, just after First Quarter. Mare Imbrium (the Sea of Rains) is a large lava flow caused by the Imbrium Event - a cataclysmic collision of an asteroid with the Moon many millions of years ago. A comparison of the two photographs will show how the appearance of lunar features changes with the angle of the Sun.
In the first photograph, Mare Imbrium (left) is separated from Mare Serenitatis (right) by two ranges of mountains, the Alps to the north and the Apennines to the south. Two large craters at upper right are Aristoteles and Eudoxus. The straight Alpine Valley may be seen cutting through the Alps. Mt Piton (height 2000 metres) is visible as a bright spot with a shadow, due south of the southern end of the Alpine Valley. Archimedes is the large crater at left. It is a walled plain 80 kilometres in diameter with a flat floor. To its right are two bowl-shaped craters, Aristillus and Autolycus. These craters are all formed by impact with large meteors. Apollo 15 landed close by the Apennines, in a small enclosed area to the right and below Archimedes, on the picture's central vertical axis.
In the second photograph, the sunrise line (called the 'terminator') has moved to the left, revealing a large walled plain in the Alps, known as Plato. South of Plato, an isolated mountain protruding through the lava flow is called Mt Pico. Ripples in the lava, called 'wrinkle ridges', are visible. The crater at lower left is Timocharis, 42 kilometres in diameter.
A detailed map of the Moon's near side is available here. A rotatable view of the Moon, with ability to zoom in close to the surface, and giving detailed information on each feature, may be downloaded here.
Click
here for a photographic animation showing the lunar phases. It also shows the Moon's wobble or libration, and how its apparent size changes as it moves from perigee to apogee each month. It takes a little while to load, but once running is very cool !<
Geocentric Events:
2013
December 1:
Limb of Moon 25 arcminutes north of the star Zuben Elgenubi
(Alpha Librae,
mv= 2.75)
at 15:58 hrs
December 1:
Limb of Moon 28 arcminutes
south of
Saturn
at 19:29 hrs
December 2:
Limb of Moon 31 arcminutes
north of
Mercury
at 08:27 hrs
December 2: Moon
1.9º
north
of the
star Graffias (Beta 1
Scorpii, mv=
2.56)
at 21:53 hrs
December 5: Moon 2.1º
north
of Pluto
at 09:09 hrs
December 6: Moon 7.9º
north
of Venus
at 07:21 hrs
December 6: Moon
1.3º
north
of the
star Dabih (Beta 1 Capricorni,
mv=
3.05)
at 23:44 hrs
December 7: Mercury 17
arcminutes north of
the star Dschubba (Delta Scorpii, mv=
2.29)
at 10:59 hrs
December 7: Mercury 29
arcminutes south of the
star Graffias (Beta 1
Scorpii, mv=
2.56)
at 16:57 hrs
December 8: Moon 6º
north
of
Neptune at 23:41 hrs
December 10: Jupiter 15 arcminutes
north of the star Wasat (Delta Geminorum,
mv=
3.5)
at 22:19 hrs
December 11: Moon 3.3º
north
of Uranus at 15:09
hrs
December 17: Limb of Moon 1º
south
of the star Zeta Tauri
(mv=
2.97) at 18:03 hrs
December 18: Uranus at eastern stationary
point at 01:39 hrs (diameter = 3.5")
December 19: Moon 4.7º
south of Jupiter at 15:36
hrs
December 22: Summer solstice at 03:05 hours
December 22: Venus at eastern stationary
point at 08:47 hrs (diameter = 52.3", phase = 12.3%)
December 22: Mercury at aphelion at 09:51
hrs (diameter = 4.7")
December 26: Moon 4.3º
south of Mars at 09:54 hrs
December 27: Moon
1.2º
north of the star
Spica
(Alpha Virginis,
mv= 0.98)
at 13:03 hrs
December 28: Mercury 32 arcminutes
north of the star Kaus Borealis
(Lambda Sagittarii,
mv= 2.82)
at 22:51 hrs
December 29: Moon
1.1º
north
of the star Zuben Elgenubi
(Alpha Librae,
mv= 2.75)
at 02:36 hrs
December 29: Limb of Moon 30 arcminutes
south of Saturn at 11:09
hrs
December 29: Mercury in superior conjunction
at 16:07 hrs (diameter = 4.7")
December 30:
Moon
1.5º
north of
the star Graffias (Beta 1
Scorpii, mv=
2.56)
at 09:03 hrs
December 30: Uranus at eastern quadrature at
14:51 hrs (diameter = 3.5")
December 31: Mercury 4.6º
south
of Pluto at 18:50
hrs
2014
January 1:
Mercury 1.6º
north of the star
Nunki
(Sigma Sagittarii,
mv= 2.04)
at 18:00 hrs
January 1:
Limb of Moon 39 arcminutes north of Pluto at 12:34 hrs
January 1:
Moon 5º
north of Mercury at
16:48 hrs
January 2:
Pluto in conjunction with the Sun at 04:51 hrs (diameter = 0.1")
January 2:
Limb of Moon 51 arcminutes north of Venus at 12:11 hrs
January 3:
Limb of Moon 22 arcseconds north of the star Dabih (Beta 1 Capricorni,
mv=
3.05)
at 08:20 hrs
January 3:
Mars at aphelion at 09:55 hrs (diameter = 7.0")
January 3:
Mars at western quadrature at 10:04 hrs (diameter = 7.0")
January 4:
Earth at perihelion at 01:18 hrs
January 5:
Moon 5.3º
north of Neptune at 06:58 hrs
January 6:
Jupiter at opposition at 06:59 hrs (diameter = 46.8")
January 7:
Moon 3.6º
north of Uranus at 21:45 hrs
January 11:
Venus at inferior conjunction at 22:26 hrs (diameter = 62.7")
January 14:
Moon 1.1º
south
of the star Zeta Tauri
(mv=
2.97) at 01:32 hrs
January 15:
Moon 4.6º
south of Jupiter at 14:51 hrs
January 23:
Moon 3.1º
south of Mars at 14:16 hrs
January 23:
Moon
1.9º
north of the star Spica
(Alpha Virginis,
mv= 0.98)
at 19:59 hrs
January 24:
Venus at perihelion at 13:35 hrs (diameter = 57.2")
January 25:
Moon
1º
north
of the star Zuben Elgenubi
(Alpha Librae,
mv= 2.75)
at 13:17 hrs
January 25:
Moon occults Saturn between 22:21 and 23:03 hrs
January 26:
Moon 2.2º
north
of the star Graffias (Beta 1
Scorpii, mv=
2.56)
at 19:21 hrs
January 26:
Mercury 1.8º
north
of the star Deneb Algedi
(Delta
Capricorni, mv=
2.85) at
22:24 hrs
January 29:
Moon 2.2º
north of Pluto at 10:25 hrs
January 29:
Moon 1.9º
south of Venus at 13:42 hrs
January 30:
Moon
1.1º
north
of Dabih
(Beta 1 Capricorni,
mv=
3.05)
between 21:09 hrs and
January 31:
Mercury at Greatest Elongation East (18.2º)
at 19:10 hrs (diameter = 7.0")
The Planets for this month:
Mercury:
Venus:
This, the brightest planet, is still a prominent object in the western evening sky, and on December 1 sets about three hours and ten minutes after the Sun, at 9:38 pm. On December 1 Venus will be a brilliant crescent in the telescope, with a phase of 30%. Venus will be moving eastward through the stars of Sagittarius at the beginning of the month. This movement will slow down until December 20, when Venus will reverse direction and head westwards towards the Sun. This is because Venus is preparing to overtake the Earth. As it approaches us, its angular diameter will increase from 37 arcseconds on December 1 to 59 arcseconds on December 31. Over the same period, it will be increasingly turning its dark side in our direction, so that its phase will drop from 30% to 4%. The combination of increasing angular diameter but decreasing phase means that its brightness changes very little, decreasing only from magnitude -4.6 to -4.4. The waxing crescent Moon will be just to the right of Venus on December 5 and 6, and on January 2.(The coloured fringes to the first and third images below are due to refractive effects in our own atmosphere, and are not intrinsic to Venus. The planet was closer to the horizon when these images were taken than it was for the second photograph, which was taken when Venus was at its greatest elongation from the Sun).
June 2013 October 2013 December 2013
Click here for a photographic animation showing the Venusian phases. Venus is always far brighter than anything else in the sky except for the Sun and Moon. Up until June in 2012, Venus appeared as an 'Evening Star', but after that it became a 'Morning Star'. Each of these appearances lasts about eight to nine months. Venus became an 'Evening Star' again last May, but will become a 'Morning Star' next April.
Because Venus was visible as the 'Evening Star' and as the 'Morning Star', astronomers of ancient times believed that it was two different objects. They called it Hesperus when it appeared in the evening sky and Phosphorus when it was seen before dawn. They also realised that these objects moved with respect to the so-called 'fixed stars' and so were not really stars themselves, but planets (from the Greek word for 'wanderers'). When it was finally realised that the two objects were one and the same, the two names were dropped and the Greeks applied a new name Aphrodite (Goddess of Love) to the planet, to counter Ares (God of War). We use the Roman versions of these names, Venus and Mars, for these two planets.
Mars:
From about 1:30 am, Mars may be found in the constellation Virgo, close to the Magnitude 3.6 star Zavijava (Beta Virginis). Orange in colour, it will be rising above the eastern horizon. On the morning of December 26, the Last Quarter Moon will be just above Mars. On the morning of December 29, Mars will be about 40 arcminutes from the magnitude 2.9 star, Porrima.
In this image, the south polar cap of Mars is easily seen. Above it is a dark triangular area known as Syrtis Major. Dark Sinus Sabaeus runs off to the left, just south of the equator. Between the south polar cap and the equator is a large desert called Hellas. The desert to upper left is known as Aeria, and that to the north-east of Syrtis Major is called Isidis Regio. Photograph taken in 1971.
Jupiter:
This gas giant planet is now passing through the constellation of Gemini in the morning sky. It is found near the navel of the second twin, named Pollux. On December 1, it rises at about 9:15 pm, and so can be observed from about 11 pm on. On December 10 Jupiter will be about 15 arcminutes north of the magnitude 3.5 star, Wasat (Delta Geminorum). On December 19 the waning gibbous Moon will be about 5 degrees to the right of Jupiter.
Saturn: The ringed planet left the evening sky and passed on the far side of the Sun (conjunction) on November 6. It has now reappeared in the early morning sky, rising just before the Sun.
Uranus: At the beginning of December, this ice giant planet is visible all evening, and is at its best for viewing. It culminates at 7:45 pm. Currently on the boundary of the constellations Pisces and Cetus, Uranus has a magnitude of 5.7, near the limit of the unaided eye. Its apparent diameter is 4 arcseconds. On December 1, Uranus will be only one arcminute away from an 11th magnitude star, GSC 13:241. The waxing gibbous Moon will be close by Uranus on the night of December 11.
Neptune: The icy blue planet is in the constellation of Aquarius at present, and reached eastern quadrature (culminating at sundown) on November 25. At the beginning of December it will be two handspans west-north-west of the zenith at 7:30 pm. Neptune is a telescopic object - its magnitude is 7.9, and its angular diameter is 2 arcseconds. The waxing crescent Moon will be about 6 degrees to the right of Neptune on the night of December 8.
Neptune, photographed from Nambour on October 31, 2008
Pluto:
The erstwhile ninth and most distant planet is a faint 14.2 magnitude object in the constellation Sagittarius, near the boundary with Scutum (The Shield). It may be found just above the handle of Sagittarius's 'Teapot'. It is poorly placed for viewing this month, being low in the west-south-west as darkness falls. It will leave the evening sky when it passes through conjunction with the Sun on January 2, 2014. Pluto's angular diameter is 0.13 arcseconds, less than one twentieth of the size of Neptune.
The movement of Pluto in two days, between 13 and 15 September, 2008. Pluto is the one object that has moved.
Width of field: 200 arcseconds
Meteor
Showers:
Phoenicids
December 7
Waxing crescent Moon, 16% sunlit ZHR =
6
Geminids
December 15
Waxing gibbous Moon, 90% sunlit ZHR =
90
Radiant: Near the star Achernar
Radiant:
Radiant: Near the star Kochab, in the northern constellation Ursa Minor.
Use this
Fluxtimator to calculate the number of meteors predicted per hour for any meteor swarm on any date, for any place in the world.
ZHR = zenithal hourly rate (number of meteors expected to be observed at the zenith in one hour). The
maximum phase of meteor showers usually occurs between 3 am and sunrise. The reason most meteors are observed in the pre-dawn hours is because at that time
we are on the front of the Earth as it rushes through space at 107 000 km per hour (30 km per second). We are meeting the meteors head-on, and the speed at
which they enter our atmosphere is the sum of their own speed plus ours. In the evenings, we are on the rear side of the Earth, and many meteors we see at that
time are actually having to catch us up. This means that the speed at which they enter our atmosphere is less than in the morning hours, and they burn up less
brilliantly.
Although most meteors are found in swarms associated with debris from comets, there are numerous 'loners', meteors travelling on solitary paths through space. When these enter our atmosphere, unannounced and at any time, they are known as 'sporadics'. Oan average clear and dark evening, an observer can expect to see about ten meteors per hour. They burn up to ash in their passage through our atmosphere. The ash slowly settles to the ground as meteoric dust. The Earth gains about 80 tonnes of such dust every day, so a percentage of the soil we walk on is actually interplanetary in origin. If a meteor survives its passage through the air and reaches the ground, it is called a 'meteorite'. One caused great alarm in Canada recently, being recorded on a camera mounted on the dashboard of a police cruiser. In the past, large meteorites (possibly comet nuclei or small asteroids) collided with the Earth and produced huge craters which still exist today. These craters are called 'astroblemes'. Two famous ones in Australia are Wolfe Creek Crater and Gosse's Bluff. The Moon and Mercury are covered with such astroblemes, and craters are also found on Venus, Mars, planetary satellites, minor planets, asteroids and even comets.
Comets:
Four comets near the Sun this month
Comets C/2012 S1 (ISON), C/2013 R1 (LOVEJOY), C/2012 X1 (LINEAR) plus the periodic comet 2P (ENCKE), are all in the vicinity of the Sun at the beginning of December. This means that they are close to the solar glare. As they move away from the Sun, they may brighten. Breaking news will be provided here.
Charts are available here..
Comet Lulin
This comet, (C/2007 N3), discovered in 2007 at Lulin Observatory by a collaborative team of Taiwanese and Chinese astronomers, is now heading towards the outer Solar System, and has faded below magnitude 15.
The
LINEARNearly all of these programs are based in the northern hemisphere, leaving gaps in the coverage of the southern sky. These gaps are the areas of sky where amateur astronomers look for comets from their backyard observatories.
To find out more about current comets, including finder charts showing exact positions and magnitudes, click
here. To see pictures of these comets, click here.
The 3.9 metre Anglo-Australian Telescope (AAT) at the Australian Astronomical Observatory near Coonabarabran, NSW. A large and dangerous bushfire swept through the Observatory grounds on the afternoon of January 13, 2013. The outside air temperature as shown by recording thermometers reached 104 degrees Celsius (hotter than boiling water). Though ash and debris entered some of the buildings, the numerous telescopes on the site were undamaged. Unfortunately, the astronomers' living quarters, some outbuildings and the Visitors' Centre were burnt out. The AAT returned to normal operations on the evening of February 14.
Deep Space
Sky Charts and Maps available on-line:
There are some useful representations of the sky available here. The sky charts linked below show the sky as it appears to the unaided eye. Stars rise four minutes earlier each night, so at the end of a week the stars have gained about half an hour. After a month they have gained two hours. In other words, the stars that were positioned in the sky at 8 pm at the beginning of a month will have the same positions at 6 pm by the end of that month. After 12 months the stars have gained 12 x 2 hours = 24 hours = 1 day, so after a year the stars have returned to their original positions for the chosen time. This accounts for the slow changing of the starry sky as the seasons progress.
The following interactive sky charts are courtesy of Sky and Telescope magazine. They can simulate a view of the sky from any location on Earth at any time of day or night between the years 1600 and 2400. You can also print an all-sky map. A Java-enabled web browser is required. You will need to specify the location, date and time before the charts are generated. The accuracy of the charts will depend on your computer’s clock being set to the correct time and date.
To produce a real-time sky chart (i.e. a chart showing the sky at the instant the chart is generated), enter the name of your nearest city and the country. You will also need to enter the approximate latitude and longitude of your observing site. For the Sunshine Coast, these are:
latitude: 26.6o South longitude: 153o East
Then enter your time, by scrolling down through the list of cities to "Brisbane: UT + 10 hours". Enter this one if you are located near this city, as Nambour is. The code means that Brisbane is ten hours ahead of Universal Time (UT), which is related to Greenwich Mean Time (GMT), the time observed at longitude 0o, which passes through London, England. Click
here to generate these charts._____________________________________
Similar real-time charts can also be generated from another source, by following this second link:
Click
here for a different real-time sky chart.The first, circular chart will show the full hemisphere of sky overhead. The zenith is at the centre of the circle, and the cardinal points are shown around the circumference, which marks the horizon. The chart also shows the positions of the Moon and planets at that time. As the chart is rather cluttered, click on a part of it to show that section of the sky in greater detail. Also, click on Update to make the screen concurrent with the ever-moving sky.
The stars and constellations around the horizon to an elevation of about 40o can be examined by clicking on
View horizon at this observing site
The view can be panned around the horizon, 45 degrees at a time. Scrolling down the screen will reveal tables showing setup and customising options, and an Ephemeris showing the positions of the Sun, Moon and planets, and whether they are visible at the time or not. These charts and data are from YourSky, produced by John Walker.
The charts above and the descriptions below assume that the observer has a good observing site with a low, flat horizon that
is not too much obscured by buildings or trees. Detection of fainter sky objects is greatly assisted if the observer can avoid bright lights, or, ideally, travel
to a dark sky site. On the Sunshine Coast, one merely has to travel a few kilometres west of the coastal strip to enjoy magnificent sky views. On the
Blackall Range, simply avoid streetlights. Allow your eyes about 15 minutes to become dark-adapted, a little longer if you have been watching television. Small
binoculars can provide some amazing views, and with a small telescope, the sky’s the limit.
The Eta Carinae Nebula, below the Southern Cross tonight.
The Stars and Constellations for this Month:
These descriptions of the night sky are for 10 pm on December 1 and 8 pm on December 31. Broadly speaking, the following description starts in the west and heads east, then south, then high in the south.
Setting on the western horizon is the zodiacal constellation Capricornus, the Sea Goat, in which the planet Neptune is found. Above Capricornus is Aquarius, the Water Bearer
The Great Square of Pegasus is tilted over on its left lower corner, and is setting in the north-west, being followed by Andromeda. Triangulum is above the north-north-western horizon. These constellations contain the well-known spiral galaxies M31 (in Andromeda, illustrated at the bottom of this webpage) and M33 (in Triangulum, illustrated below).
The Great Spiral M33 in Triangulum.
These large spirals are members of the Local Group of galaxies (our Milky Way is a third member), and can be easily seen with good binoculars. They
are the nearest galaxies that can be observed from the large observatories in the Northern Hemisphere. This month they are
best seen as soon as darkness falls, for then they will be closer to due north and therefore at their highest elevation.
The three main stars in Andromeda are, from left to right, Alpheratz, Mirach, and Almach , and above them is the faint constellation of Triangulum, a narrow triangle of stars. M31 lies about eight degrees (one third of a handspan) below and slightly to the left of Mirach tonight.
Above Triangulum is the zodiacal constellation of Aries, now past the meridian in the north-north- west. There are three main stars in Aries, the brightest being a second magnitude orange star called Hamal. The other two are named Sheratan and Mesarthim. M33 lies midway between Hamal and Mirach.
Cetus, the Whale, lies a little north-west of the zenith. Though this part of the sky has no really bright stars, a little more than a handspan west of the zenith is a mv 2.2 star. This is Beta Ceti, the brightest ordinary star in the constellation Cetus, the Whale. Its common name is Diphda, and it has a yellowish-orange colour. By rights, we would expect the star Menkar or Alpha Ceti to be brighter, but Menkar is actually more than half a magnitude fainter than Diphda. Menkar may be seen high in the north-east, halfway between Diphda and Aldebaran.
Cetus is a large constellation, and to the unaided eye it appears unremarkable. But it does contain a most interesting star, which even medieval people noticed. Hevelius named it Mira, the Wonderful (see below). Between Cetus and Pegasus is the zodiacal constellation of Pisces, the Fishes. Pisces is found just to the left of Aries, and this year hosts the planet Uranus.
The spectacular constellations are in the eastern half of the sky tonight. Taurus, with its two star clusters the Pleiades (or Seven Sisters, Subaru or Santa's Sleigh) and the Hyades, is high in the north-north-east (see below). The brightest star in Taurus is an orange star dominating the Hyades cluster, but not a member of it. This is Aldebaran, a K5 star with a visual magnitude of 0.87.
Below the Pleiades we can see part of the far-northern constellation of Perseus. Between the Hyades and the north-eastern horizon, the large pentagon of Auriga, the Charioteer has risen. The brightest star in this constellation is Capella, which is directly above the north-north-eastern horizon. Just above Capella is a little triangle of stars, known as 'The Kids'. The top star of Auriga's pentagon, Elnath, points towards Orion. Actually, Elnath is the second-brightest star in Taurus, and forms the tip of one of the Bull's horns.
At 10 pm at the beginning of the month, the two bright stars of Gemini, Castor and Pollux, are just rising above the theoretical north-eastern horizon. These two first magnitude stars are known as 'The Twins'. If your horizon in this direction is very low, you may be able to glimpse them, both stars rising together about five degrees apart. Pollux is the more easterly of the two. If your horizon is not low, you will have to wait a little to see these stars appear. These two stars are the twins' heads, and their feet point towards Orion. Two-thirds of the way from their heads to their feet, each twin is marked by a star at his hip, third magnitude Mebsuta for Castor, and fourth magnitude Mekbuda for Pollux. This month, Gemini is dominated by the presence of the brilliant planet Jupiter, outshining all the stars. It is located in the stomach of the second twin, near the star Wasat, and between the stars Pollux and Mekbuda.
Orion (see below) is about halfway up the sky in the east, and a bright star in Canis Minor, Procyon, is now about half-a-handspan above the eastern horizon. At midnight at mid-month, Orion will cross the meridian (the north-south line across the sky, passing through the zenith), at which time the constellation is said to ‘culminate’. Orion's Belt will be about twenty-five degrees (a little more than a handspan) north of the zenith. Sirius, the brightest star in the night sky, is south-east of Orion.
Very low in the south, Alpha Crucis (or Acrux), the brightest and most southerly star of Crux (Southern Cross) is beginning to rise. Between Crux and Sirius is a large area of the Milky Way filled with interesting objects. This was once the constellation Argo Navis, named for Jason’s famous ship used by the Argonauts in their search for the Golden Fleece. The constellation Argo was found to be too large, so modern star atlases divide it into three sections - Carina (the Keel), Vela (the Sails) and Puppis (the Stern).
Above the horizon, just to the left of due south and above Acrux, is the small constellation Musca, the Fly. Musca is a circumpolar constellation, i.e. it is always in our sky, being too close to the South Celestial Pole to set. Out of the 88 constellations, it is the only insect.
High in the south-east and two handspans from Sirius is the second brightest star in the night sky, Canopus (Alpha Carinae). On the border of Carina and Vela is the False Cross, larger and more lopsided than the Southern Cross. Both of these Crosses are actually more like kites in shape for, unlike Cygnus (the Northern Cross) they have no star at the intersection of the two cross arms. At the present time, both Crosses are upside-down.
At about thirty-five degrees above the south-western horizon, the flattened triangle of Grus, the Crane, is swinging down. To its right is the bright star Fomalhaut, a bright, white first magnitude star in the faint constellation Piscis Austrinus, the Southern Fish. Fomalhaut means 'the fish's mouth'. A planet revolving around Fomalhaut was recently photographed by the Hubble Space Telescope. Midway between -0.71 magnitude Canopus and 1.16 magnitude Fomalhaut is the 0.46 magnitude star Achernar, in the constellation Eridanus, the River.
Eridanus winds its faint way across the sky from Achernar to Cursa, these two stars marking the ends of the river. Cursa (Beta Eridani) is a 2.79 magnitude star about four degrees to the north-west of Rigel (see below).
To the right of Achernar, the faint constellation of Phoenix may be seen. Its brightest star is Ankaa, a mv 2.39 star which is about one third of the way from Achernar to Diphda. About a handspan south of Achernar is a small, faint glowing patch. This is the Small Magellanic Cloud (SMC). A handspan to its left is a larger glow, the Large Magellanic Cloud (LMC). Both of these glowing clouds are galaxies in their own right, separate from our Milky Way galaxy. They are described in greater detail in "
Two close galaxies" below. The LMC bridges two faint constellations, Dorado and Mensa. The SMC is in the constellation Tucana, the Toucan.The zodiacal constellations visible tonight, starting from the south-western horizon and heading
across
to the north-east horizon, are Capricornus, Aquarius, Pisces, Aries, Taurus and
Gemini.
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The Winged Horse and the Chained Maiden:
About half-way up the sky from the north-north-western horizon (at the end of twilight on December 1) is a large star group called the
Great Square of Pegasus. The Square (actually slightly rectangular) is unusual for the sparcity of bright stars within it.
Pegasus was the winged horse of Greek legend, and is used as a symbol by the Mobil Oil Company and TriStar Pictures. By 8.00 pm the
Square will be tilted over to the west and it will begin to set in the north-west by 11.00 pm. The stars making the four corners of the Square, starting from the top left and moving clockwise, are Markab,
Algenib, Alpheratz and Scheat. Three of these are in the constellation of Pegasus, but Alpheratz is
actually in the constellation Andromeda.
Between Alpheratz and the northern horizon, a very faint glowing oval may be seen if the sky is dark enough. You would need to be away from light pollution caused by bright lights. Binoculars will help you to find it, but it is visible faintly without optical aid. This oval is the Great Nebula in Andromeda (M31), a large spiral galaxy of over 100 million stars. The Andromeda spiral is almost a twin of our own galaxy, the Milky Way. Lying at a distance of two million light years, it is the furthest object that can be seen with the unaided eye (see "
The Andromeda Galaxy and the President of the United States" at the bottom of this page).
The Hunter and his Dogs:
Two of the most spectacular constellations in the sky may be seen rising above the eastern horizon soon after sunset in December. These are Orion the Hunter, and his large dog, Canis Major. Orion straddles the celestial equator, midway between the south celestial pole and its northern equivalent. This means that the centre of the constellation, the three stars known as Orion's Belt, rise due east and set due west. A smaller constellation, the lesser dog Canis Minor, accompanies them.Orion:
This is one of the most easily recognised constellations, as it really does give a very good impression of a human figure. From the northern hemisphere he appears to stand upright when he is high in the sky, but from our location ‘down under’ he appears lying down when rising and setting, and upside down when high in the sky. You can, though, make him appear upright when high in the sky (near the meridian), by observing him from a reclining chair, with your feet pointing to the south and your head tilted back.
Orion rising as darkness falls in December
Orion rises south-east of Taurus. If you have a fairly low eastern horizon, you will
see most of the constellation rising above the eastern horizon as soon as it gets dark at the beginning of December. The bright Rigel is
highest in the sky. The red supergiant Betelgeuse is the last of Orion's bright stars to rise.
A little north of a line joining these stars is a tiny triangle of stars marking Orion’s head. In the centre of the constellation are three stars in a line forming Orion's Belt. These are, from west to east, Mintaka, Alnilam and Alnitak. These three stars are related, and all lie at a distance of 1300 light years. They are members of a group of hot blue-white stars called the Orion Association.
To the south of the Belt, at a distance of about one Belt-length, we see another faint group of stars in a line, fainter and closer together than those in the Belt. This is Orion’s Sword. Orion’s legs are marked by brilliant Rigel and fainter Saiph. Both of these stars are also members of the Orion Association.
The Saucepan, with Belt at left, M42 at lower right.
Orion is quite a symmetrical constellation, with the Belt at its centre and the two shoulder stars off to the north and the two leg stars to the south. It is quite a large star group, the Hunter being over twenty degrees (about a handspan) tall.
The stars forming the Belt and Sword are popularly known in Australia as ‘The Saucepan’, with the Sword forming the Saucepan’s handle. This asterism appears upside-down tonight, as in the photographs above. The faint, fuzzy star in the centre of the Sword, or the Saucepan’s handle, is a great gas cloud or nebula where stars are being created. It is called the ‘Great Nebula in Orion’ or M42*.
A photograph of it appears below:
The Sword of Orion, with the Great Nebula, M42, at centre
By 8.00 pm in early December, a brilliant white star will be seen rising about one handspan to the south and lower than Orion.
This is Sirius, or Alpha Canis Majoris, and it is the brightest star in the night sky with a visual magnitude of -1.43.
It marks the heart of the hunter's dog, and has been known for centuries as the Dog Star. As he rises, the dog is on his
back with his front foot in the air. The star at the end of this foot is called Mirzam. It is also known as Beta Canis
Majoris, which tells us that it is the second-brightest star in the constellation. Mirzam is about one-third of a handspan above
Sirius. The hindquarters of the Dog are indicated by a large right-angled triangle of
stars located to the right of Sirius and tilted. The end of his tail is the lower-right corner of the triangle, about one
handspan south (to the right) of Sirius. The star at the root of the Dog's tail is called Wezen, and the one at the tip of his
tail is called Aludra. The star Adhara marks his back foot. The Dog's head is shown by a faint outline of fourth and fifth magnitude stars. Both Sirius and Rigel are bright white stars and each has a tiny, faint white
dwarf companion. Whereas a small telescope can reveal the companion to Rigel quite easily, the companion to Sirius the Dog Star,
(called ‘the Pup’), can only be observed by using a powerful telescope with excellent optics on a night of good 'seeing', as
it is very close to brilliant Sirius and is usually lost in the glare.
Canis
Major as it appears in the east soon after sunset in December
This small constellation contains only two main stars, the brighter of which is Procyon (Alpha Canis Minoris). This yellow-white star of mv= 0.5 forms one corner of a large equilateral triangle, the other two corners being the red Betelgeuse and white Sirius. Beta Canis Minoris is also known as Gomeisa, a blue-white star of mv= 3.1. Procyon rises in the east soon after 9.00 pm at the beginning of December.
Taurus, the Bull:
What is Orion hunting? About a handspan to the left of Orion's Belt is a bright orange star, Aldebaran. It is the brightest star in the constellation Taurus, the Bull. This orange star appears at the foot of a cluster of stars with the appearance of a capital A or inverted V. This cluster is called the Hyades, and seemed to the ancients like the face of a bull, with Aldebaran as his angry orange eye. Being in the southern hemisphere, we see it upside down. Actually, Aldebaran is not physically connected with the Hyades cluster, being much closer, but in the same line of sight.
Half a handspan to the left of the Hyades cluster, and a little higher above the horizon, is another cluster, smaller and fainter. This is the Pleiades, a small group like a question mark. It is often called the Seven Sisters, although excellent eyes are needed to detect the seventh star without binoculars or telescope. The group is also known as ‘Santa’s Sleigh’, as it appears around Christmas time. All the stars in this cluster are hot and blue. They are also the same age, as they formed as a group out of a single gas cloud or nebula. There are actually more than 250 stars in the Pleiades, and this cluster marks the Bull's shoulder. All of these stars are completely outshone by brilliant Jupiter, close by.
T
he Pleiades is the small cluster at centre left, while the Hyades is the much larger grouping at centre right.
Wisps of the nebula which formed the Pleiades can be seen around the brighter stars in the cluster.
Mira, the Wonderful:
The amazing thing about the star Mira or Omicron Ceti is that it varies dramatically in brightness, rising to magnitude 2 (brighter than any other star in Cetus), and then dropping to magnitude 10 (requiring a telescope to detect it), over a period of 332 days.
This drop of eight magnitudes means that its brightness diminishes over a period of five and a half months to one six-hundredth of what it had been, and then over the next five and a half months it regains its original brightness. To the ancients, they saw the familiar star fade away during the year until it disappeared, and then it slowly reappeared again. Its not surprising that it became known as Mira, meaning 'The Wonderful' or 'The Miraculous One'.
We now know that many stars vary in brightness, even our Sun doing so to a small degree, with a period of 11 years. One type of star varies, not because it is actually becoming less bright in itself, but because another, fainter star moves around it in an orbit roughly in line with the Earth, and obscures it on each pass. This type of star is called an eclipsing variable and they are very common.
The star Mira though, varies its light output because of processes in its interior. It is what is known as a pulsating variable. Stars of the Mira type are giant pulsating red stars that vary between 2.5 and 11 magnitudes in brightness. They have long, regular periods of pulsation which lie in the range from 80 to 1000 days.
Last July Mira brightened to second magnitude, but then faded again as expected. It is now quite faint once again.
Mira near minimum, 26 September 2008 Mira near maximum, 22 December 2008
Astronomers using a NASA space telescope, the Galaxy Evolution Explorer, have spotted an amazingly long comet-like tail behind Mira as the star streaks through space.
Galaxy Evolution Explorer - "GALEX" for short-scanned the well-known star during its ongoing survey of the entire sky in ultraviolet light. Astronomers then noticed what looked like a comet with a gargantuan tail. In fact, material blowing off Mira is forming a wake 13 light-years long, or about 20,000 times the average distance of Pluto from the sun. Nothing like this has ever been seen before around a star. More, including pictures
Double stars:
Estimates vary that between 15% and 50% of stars are single bodies like our Sun, although the latest view is that less than 25% of stars are solitary. At least 30% of stars and possibly as much as 60% of stars are in double systems, where the two stars are gravitationally linked and orbit their mutual centre of gravity. Such double stars are called binaries. The remaining 20%+ of stars are in multiple systems of three stars or more. Binaries and multiple stars are formed when a condensing Bok globule or protostar splits into two or more parts.
Binary stars may have similar components (Alpha Centauri A and B are both stars like our Sun), or they may be completely dissimilar, as with Albireo (Beta Cygni, where a bright golden giant star is paired with a smaller bluish main sequence star).
The binary stars Rigil Kentaurus (Alpha Centauri) at left, and Beta Cygni (Albireo), at right.
Acrux, the brightest star in the Southern Cross, is also known as Alpha Crucis. It is a close binary, circled by a third dwarf companion.
Alpha Centauri (also known as Rigil Kentaurus, Rigil Kent or Toliman) is a binary easily seen with the smallest telescope. The components are both solar-type main sequence stars, one of type G and the other, slightly cooler and fainter, of type K. Through a small telescope this star system looks like a pair of distant but bright car headlights. Alpha Centauri A and B take 80 years to complete an orbit, but a tiny third component, the 11th magnitude red dwarf Proxima
,
Close-up of the star field around Proxima Centauri
Knowing the orbital period of the two brightest stars A and B, we can apply Kepler’s Third Law to find the distance they are apart. This tells us that Alpha Centauri A and B are about 2700 million kilometres apart or about 2.5 light hours. This makes them a little less than the distance apart of the Sun and Uranus (the orbital period of Uranus is 84 years, that of Alpha Centauri A and B is 80 years.)
Albireo (Beta Cygni) is sometimes described poetically as a large topaz with a small blue sapphire. It is one of the sky’s most beautiful objects. The stars are of classes G and B, making a wonderful colour contrast. It lies at a distance of 410 light years, 95 times further away than Alpha Centauri.
Binary stars may be widely spaced, as the two examples just mentioned, or so close that a telescope is struggling to separated them (Acrux, Castor, Antares, Sirius). Even closer double stars cannot be split by the telescope, but the spectroscope can disclose their true nature by revealing clues in the absorption lines in their spectra. These examples are called spectroscopic binaries. In a binary system, closer stars will have shorter periods for the stars to complete an orbit. Eta Cassiopeiae takes 480 years for the stars to circle each other. The binary with the shortest period is AM Canum Venaticorum, which takes only 17½ minutes.Sometimes one star in a binary system will pass in front of the other one, partially blocking off its light. The total light output of the pair will be seen to vary, as regular as clockwork. These are called eclipsing binaries, and are a type of variable star, although the stars themselves usually do not vary.
Why are some constellations bright, while others are faint ?
Our galaxy is shaped like a flattened disc containing about 100 million stars. Our own star, the Sun, with its Solar System is located about two-thirds of the distance out from the centre. When we look along the plane of the galaxy, either in towards the centre or out towards the edge, we are looking along the disc through the teeming hordes of stars, clusters, dust clouds and nebulae. In the sky, the galactic plane gives the appearance which we call the Milky Way, a brighter band of light crossing the sky. This part of the sky is very interesting to observe with binoculars or telescope. The brightest and most spectacular constellations, such as Crux, Canis Major, Orion and Scorpius are located close to the Milky Way.
If we look at ninety degrees to the plane, either straight up and out of the galaxy or straight down, we are looking through comparatively few stars and gas clouds and so can see out into deep space. These are the directions of the north and south galactic poles, and because we have a clear view in these directions to distant galaxies, these parts of the sky are called the intergalactic windows. The southern window is in the constellation Sculptor, not far from the star Fomalhaut. This window is well-placed for viewing this month, and many distant galaxies can be observed in this area of the sky. The northern window is between the constellations Virgo and Coma Berenices, roughly between the stars Denebola and Arcturus. It is below the horizon in the evenings this month.
Some of the fainter and apparently insignificant constellations are found around these windows, and their lack of bright stars, clusters and gas clouds presents us with the opportunity to look across the millions of light years of space to thousands of distant galaxies.
Some fainter constellations:
Between the two Dogs is the constellation Monoceros the Unicorn, undistinguished except for the presence of the remarkable Rosette Nebula. South of Orion is a small constellation, Lepus the Hare. Between Lepus and the star Canopus is the star group Columba the Dove. Between the zenith and the south-western horizon are a number of small, faint constellations, Phoenix, Hydrus, Reticulum, Indus and Pavo. Clustered around the South Celestial Pole are Dorado, Octans, Apus, Chamaeleon, Mensa and Volans.
Finding the South Celestial Pole:
The South Celestial Pole is that point in the southern sky around which the stars rotate in a clockwise direction. The Earth's axis is aimed exactly at this point. For an equatorially-mounted telescope, the polar axis of the mounting also needs to be aligned exactly to this point in the sky for accurate tracking to take place.
To find this point, first locate the Southern Cross. Project a line from the orange star at the top of the Cross (Gacrux) to the star at its base (Acrux) and continue straight on towards the south (to the left) for another four Cross lengths. This will locate the approximate spot. There is no bright star to mark the Pole, whereas in the northern hemisphere they have Polaris (the Pole Star) to mark fairly closely the North Celestial Pole.
Another way to locate the South Celestial Pole is to draw an imaginary straight line joining Beta Centauri in the south-west to Achernar in the south-east. Bisect this imaginary line to locate the pole.
Neither of these methods will work in Queensland during December evenings as both the Southern Cross and Beta Centauri are below the horizon. However, they will have risen by 1 am. Interesting photographs of this area can be taken by using a camera on time exposure. Set the camera on a tripod pointing due south, and open the shutter for thirty minutes or more. The stars will move during the exposure, being recorded on the film as short arcs of a circle. The arcs will be different colours, like the stars are. All the arcs will have a common centre of curvature, which is the south celestial pole.
A wide-angle view of trails around the South Celestial Pole, with Scorpius and Sagittarius at left, Crux and Centaurus at top, and Carina and False Cross at right.
Star trails between the South Celestial Pole and the southern horizon. All stars that do not pass below the horizon are circumpolar.
Star Clusters:
The two clusters in Taurus, the Pleiades and the Hyades, are known as Open Clusters or Galactic Clusters. The name 'open cluster' refers to the fact that the stars in the cluster are grouped together, but not as tightly as in globular clusters (see below). The stars appear to be loosely arranged, and this is partly due to the fact that the cluster is relatively close to us, i.e. within our galaxy, hence the alternate name, 'galactic cluster'. These clusters are generally formed from the condensation of gas in a nebula into stars, and some are relatively young.
The photograph below shows a typical open cluster,
M7*. It lies in the constellation Scorpius, just above the scorpion's sting. It lies in the direction of our gal
Galactic Cluster M7 in Scorpius
Outside the plane of our galaxy, there is a halo of Globular Clusters. These are very old, dense clusters, containing perhaps several hundred thousand stars. These stars are closer to each other than is usual, and because of its great distance from us, a globular cluster gives the impression of a solid mass of faint stars. Many other galaxies also have a halo of globular clusters circling around them.
The largest and brightest globular cluster in the sky is
NGC 5139**, also known as Omega Centauri. It has a slightly oval shape. It is an outstanding winter object, but this month it is below the horizon for much of the night. Shining at fourth magnitude, it is faintly visible to the unaided eye, but is easily seen with binoculars, like a light in a fog. A telescope of 20 cm aperture or better will reveal its true nature, with hundreds of faint stars giving the impression of diamond dust on a black satin background. It lies at a distance of 5 kiloparsecs, or 16 300 light years.<
Although Omega Centauri is below the horizon in the evenings this month, there is another remarkable globular, second only to Omega, which is in a good position. Close to the SMC (see "
Two close galaxies
The globular cluster 47 Tucanae
Observers aiming their telescopes towards the SMC generally also look at the nearby 47 Tucanae, but there is another globular cluster nearby which is also worth a visit. This is NGC 362, which is less than half as bright as the other globular, but this is because it is more than twice as far away. Its distance is 12.6 kiloparsecs or 41 000 light years, so it is about one-fifth of the way from our galaxy to the SMC. Both NGC 104 and NGC 362 are always above the horizon for all parts of Australia south of the Tropic of Capricorn.
* M7: This number means that this galactic cluster in Scorpius is No. 7 in a list of 103 astronomical objects compiled and published in 1784 by Charles Messier. Charles was interested in the discovery of new comets, and his aim was to provide a list for observers of fuzzy nebulae and clusters which could easily be reported as comets by mistake. Messier's search for comets is now just a footnote to history, but his list of 103 objects is well known to all astronomers today, and has even been extended to 110 objects.
** NGC 5139: This number means that Omega Centauri is No. 5139 in the New General Catalogue of Non-stellar Astronomical Objects. This catalogue was first published in 1888 by J. L. E. Dreyer under the auspices of the Royal Astronomical Society, as his New General Catalogue of Nebulae and Clusters of Stars. As larger telescopes built early in the 20th century discovered fainter objects in space, and also dark, obscuring nebulae and dust clouds, the NGC was supplemented with the addition of the Index Catalogue (IC). Many non-stellar objects in the sky have therefore NGC numbers or IC numbers. For example, the famous Horsehead Nebula in Orion is catalogued as IC 434. The NGC was revised in 1973, and lists 7840 objects.
The recent explosion of discovery in astronomy has meant that more and more catalogues are being produced, but they tend to specialise in particular types of objects, rather than being all-encompassing, as the NGC / IC try to be. Some examples are the Planetary Nebulae Catalogue (PK) which lists 1455 nebulae, the Washington Catalogue of Double Stars (WDS) which lists 12 000 binaries, the General Catalogue of Variable Stars (GCVS) which lists 28 000 variables, and the Principal Galaxy Catalogue (PGC) which lists 73 000 galaxies. The largest modern catalogue is the Hubble Guide Star Catalogue (GSC) which was assembled to support the Hubble Space Telescope's need for guide stars when photographing sky objects. The GSC contains nearly 19 million stars brighter than magnitude 15.
Two close galaxies:
At 10 pm on December 1, two faint smudges of light may be seen high in the south. These are the two Clouds of Magellan, known to astronomers as the LMC (Large Magellanic Cloud) and the SMC (Small Magellanic Cloud). The LMC is to the left of the SMC, and is noticeably larger. They lie at distances of 190 000 light years for the LMC, and 200 000 light years for the SMC. They are about 60 000 light years apart. These dwarf galaxies circle our own much larger galaxy, the Milky Way. The LMC is slightly closer, but this does not account for its larger appearance. It really is larger than the SMC, and has developed as an under-sized barred spiral galaxy.
The Large Magellanic Cloud - the bright knot of gas to left of centre is the famous Tarantula Nebula (below)
These two Clouds are the closest galaxies to our own, but lie too far south to be seen by the large telescopes in Hawaii, California and Arizona. They are 15 times closer than the famous Andromeda and Triangulum galaxies in the northern half of the sky, and so can be observed in much clearer detail. Our great observatories in Australia, both radio and optical, have for many years been engaged in important research involving these, our nearest inter-galactic neighbours.
The Andromeda Galaxy and the President of the United States:
In 1901 U.S.A. President William McKinley was assassinated and his Vice-President, Theodore Roosevelt
, took his place. Theodore became a popular President, and was elected in his own right in 1904 for a second term. He was known as Teddy Roosevelt, and the Teddy Bear is named after him. As President he was a dynamic, vigorous and energetic man, very keen on preserving the wonders of nature through the creation of national parks, forests, and natural monuments such as Rainbow Bridge.Teddy made the acquaintance of noted American naturalist, scientist, explorer and author
William Beebe who shared his love of nature. They became friends and would meet regularly for dinner and an evening's conversation, sometimes with friends of similar interests. Both men had strong egos, but recognised the dangers of pride in themselves and in their accomplishments.It is said that after dinner, Roosevelt, Beebe and their friends would step outside for cigars and lengthy discussions about world affairs. At the conclusion, they would look up at the starry sky. Roosevelt or Beebe would point out a small, faint smudge of light close to the Great Square of Pegasus and they would both recite, almost as a litany, something similar to the following:
"That is the Spiral Galaxy in Andromeda. It is as large as our Milky Way. It is one of a hundred million galaxies. It consists of one hundred million suns, many larger than our sun." The President would then turn to the others. "Now I think we are small enough," he would say. "Let's go to bed."
Whereas from the latitude of Washington D.C. the Andromeda Galaxy is visible for most of the year, f
rom Australia it is so far north (41 degrees north declination) that it is only visible in the evenings during spring and early summer. For us, this magnificent galaxy is due north at 8 pm on December 1, about one handspan above the horizon.
The Great Galaxy in Andromeda, M31, photographed at Starfield Observatory with an off-the-shelf digital camera on 16 November 2007.
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