The Night Sky January 2013
Compiled by Ian Morison
A great month to view Jupiter
This page, updated monthly, will let you know some of the things that you can look out for in the night sky. It lists the phases of the Moon, where you will see the naked-eye planets and describes some of the prominent constellations in the night sky during the month.
Image of the Month
The Earth at night
NASA, NOAA NGDC, Suomi-NPP, Earth Observatory.This image was built up from images taken by the Suomi-NPP satellite in a polar orbit 512 miles above Earth. The city lights identify major population areas - but also show when one should go to find dark skies! In the UK, Mid-Wales, North Devon and parts of Scotland are the least light polluted. The surprise, for me, was the amount light seen coming from the mid-west of Australia.
Highlights of the Month
January - a great month to view Jupiter!
This is the third of three great months to observe Jupiter. It now lies in Taurus and so is high in the ecliptic and hence, when due south, at an elevation of ~60 degrees. It is looking somewhat different than in the last few years as the north equatorial belt has become quite broad. The Great Red Spot is currently a pale shade of pink but can be easily seen as a large feature in the South Equatorial Belt. Jupiter was at opposition on the 3rd of December so, this month, will cross the meridian in the mid-evening - ideal for observing! After its apparition next year it will be moving towards more southerly parts of the ecliptic so will be at lower elevations when crossing the meridian and will thus be seen through thicker layers of the atmosphere.The features seen in the Jovian atmosphere have been changing quite significantly over the last few years - for a while the South Equatorial Belt vanished completely but has now returned to its normal wide state. The diagram on right shows the main Jovian features as imaged by the author at the beginning of December 2012. The image by Damian Peach was taken with a 14 inch telescope in Barbados where the seeing can be particularly good. This image won the "Astronomy Photographer of the Year" competition in 2011.
See more of Damian Peach's images: Damian Peaches Website"
January: Look for the Great Red Spot on Jupiter
This list gives some of the best evening times during January to observe the Great Red Spot which should then lie on the central meridian of the planet.
1st 20:20 20th 21:01
3rd 21:58 22nd 22:40
5th 23:37 25th 20:10
8th 21:06 27th 21:48
13th 20:14 29th 23:27
15th 21:53 30th 19:18
January 6th - 1 hr before Dawn: Saturn and the Moon.
This month, Saturn, in the constellation Virgo, is visible in the pre-dawn sky and will make a nice grouping with a waning crescent Moon lying below the star Spica in Virgo.
Early January after sunset: Jupiter and Vesta lying between the Hyades and Pleiades
Looking up at about 45 degrees elevation, the sky will be dominated by Jupiter hanging between the Pleaides Cluster and the Hyades Cluster with the "interloper" star, Aldebaran acting as the "eye of the bull".
Lying 2 degrees up to the left of Aldebaran is the 7th magnitude asteroid, Vesta. It will thus be seen in a pair of binoculars when Aldebaran is towards the bottom of the field of view. The chart shows it movements from the 5th to the 11th of January. It will be easiest to spot on the 10th and 11th when it will appear as one of an equal double - Vesta and the star having almost identical brightness.
January 10th - 45 minutes before Dawn: Venus and a thin waning crescent Moon
On the 10th, Venus, ending its morning apparition, will be seen low above the horizon and joined by a thin waning crescent Moon.
January 13th - 1 hour after sunset: A last chance to spot Mars along with a thin crescent Moon.
We will have a last chance to spot Mars,on the 13th lying below a very thin waxing crescent Moon. See if you can spot the "Earthshine", the dark side of the Moon illuminated by light reflected from clouds in the Earth's atmosphere.
January 21st: Two Great Lunar Craters
Two great Lunar Craters: Tycho and Copernicus
This is a great night to observe two of the greatest craters on the Moon, Tycho and Copernicus, as the terminator is nearby. Tycho is towards the bottom of Moon in a densely cratered area called the Southern Lunar Highlands. It is a relatively young crater which is about 108 million years old. It is interesting in that it is thought to have been formed by the impact of one of the remnents of an asteroid that gave rise to the asteroid Baptistina. Another asteroid originating from the same breakup may well have caused the Chicxulub crater 65 million years ago. It has a diameter of 85 km and is nearly 5 km deep. At full Moon - seen in the image below - the rays of material that were ejected when it was formed can be see arcing across the surface. Copernicus is about 800 million years old and lies in the eastern Oceanus Procellarum beyond the end of the Apennine Mountains. It is 93 km wide and nearly 4 km deep and is a clasic "terraced" crater. Both can be seen with binoculars.
A Messier Object imaged with the Faulkes Telescope: Messier 1 - The Crab Nebula
The Crab Nebula, M16, imaged by Nik Szymanek.
This image was taken using the Faulkes Telescope North by Nik Szymanek - one of the UK's leading astro-photograpers. The Crab nebula - the first entry in Charles Messier's catalogue - is the remnant of a supernovae that was seen to explode in the year 1054. It is visible as the lower right of the pair of stars at the centre of the nebula and is a "neutron star" just 30km across but weighing more than our Sun! Under the intense pressure of gravity, the protons and electrons fused to form neutrons and the compact object became stable as gravity was opposed by "neutron degeneracy pressure" - a quantum mechanical force. It is now spinning just under 30 times a second and emitting two opposed beams of light and radio waves which pass across our location in space. We thus detect very regular pulses and so objects like this are called pulsars. At 8.4 magnitudes it is easily seen in a small telescopes under dark transparent skies appearing as a smudge of light which is a little underwhelming to see!
Learn more about the Faulkes Telescopes and how schools can use them: Faulkes Telescope"
Observe the International Space Station
The International Space Station and Jules Verne passing behind the Lovell Telescope on April 1st 2008.
Image by Andrew Greenwood
Use the link below to find when the space station will be visible in the next few days. In general, the space station can be seen either in the hour or so before dawn or the hour or so after sunset - this is because it is dark and yet the Sun is not too far below the horizon so that it can light up the space station. As the orbit only just gets up the the latitude of the UK it will usually be seen to the south, and is only visible for a minute or so at each sighting. Note that as it is in low-earth orbit the sighting details vary quite considerably across the UK. The NASA website linked to below gives details for several cities in the UK. (Across the world too for foreign visitors to this web page.)
Note: I observed the ISS three times recently and was amazed as to how bright it has become.
Find details of sighting possibilities from your location from: Location Index
See where the space station is now: Current Position
The Moon at 3rd Quarter. Image, by Ian Morison, taken with a 150mm Maksutov-Newtonian and Canon G7.
Just below the crator Plato seen near the top of the image is the mountain "Mons Piton". It casts a long shadow across the maria from which one can calculate its height - about 6800ft or 2250m.
|new moon||first quarter||full moon||last quarter|
|January 11th||January 18th||January 26th||January 4th|
Some Lunar Images by Ian Morison, Jodrell Bank Observatory: Lunar Images
A World Record Lunar Image
To mark International Year of Astronomy, a team of British astronomers have made the largest lunar image in history and gained a place in the Guinness Book of Records! The whole image comprises 87.4 megapixels with a Moon diameter of 9550 pixels. This allows details as small as 1km across to be discerned! The superb quality of the image is shown by the detail below of Plato and the Alpine Valley. Craterlets are seen on the floor of Plato and the rille along the centre of the Alpine valley is clearly visible. The image quality is staggering! The team of Damian Peach, Pete lawrence, Dave Tyler, Bruce Kingsley, Nick Smith, Nick Howes, Trevor Little, David Mason, Mark and Lee Irvine with technical support from Ninian Boyle captured the video sequences from which 288 individual mozaic panes were produced. These were then stitched together to form the lunar image.
Please follow the link to the Lunar World Record website and it would be really great if you could donate to Sir Patrick Moore's chosen charity to either download a full resolution image or purchase a print.
Jupiter is now well up in the eastern sky after sunset and crosses the meridian, highest in the sky at 21:00 on January 1st and at 19:30 on the 30th. When due south, it will lie some 60 degrees above the horizon in the constellation of Taurus, the Bull. Shining at magnitude -2.7, it starts January lying just 5.25 degrees to the upper right of the star Aldebaran, the eye of the Bull. Jupiter is still moving westwards in the sky in retrograde motion and will do so until the beginning of February, so whilst its magnitude drops slightly to -2.5 it moves very little across the sky. During the month its angular diameter drops only slightly from 46.8 to 43.1 arc seconds so even a small telescope will still show plenty of detail with the bright zones and darker bands crossing the disk and up to four Gallilean moons visible as they weave their way around the giant planet. The times given in the highlight above will tell you when the Great Red Spot is easily visible in the evening.
See highlights above.
Saturn, lying in Libra, rises at 2:30 am as the year begins and by midnight at month's end so will be visible well above the eastern horizon before dawn. Its magnitude remains almost constant at +0.6 magnitudes whilst its angular size increases from 16.2 to 17.0 arc seconds. The good news is that the rings have now opened out to just over 19 degrees from the line of sight and will be at their best for 6 years! We are now observing the planet's southern hemisphere whilst much of the northern hemisphere will be hidden by the rings. Saturn is at 90 degrees in angle from the Sun on the 30th so will then be side-lit and showing the shadow of the planet on the rings. Saturn is moving slowly towards the wide double star Alpha Librae with the seperation droping from 6 to 4.5 degrees during the month. With a small scope one should now be able to spot Cassini's Division within the rings if the "seeing" is good but, sadly, Saturn is now lying in the more southerly part of the ecliptic so its elevation will not be that high when seen from our northern latitudes.
See highlight above.
Mercury, is essentially invisible to the unaided eye all month. On the first of January it must be glimpsed well down the to left of Venus before dawn and, at the very end of the month, down to the lower left of Mars after Sunset.
See highlight above.
Mars, moving eastwards from Capricornus into Aquarius on the 29th, is visible low in the west after sunset whilst its rapid motion through the heavens keeps it visible throughout the month - as it has done so for around 4 months now! It can be seen at an elevation of about 10 degrees in the southwest 45 minutes after sunset on Jan 1st but this will have reduced to 6 degrees by month's end It shines at magnitude +1.2 whilst its angular diameter falls from 4.2 to 4.1 arc seconds so it is very unlikly that any surface markings could be seen on its salmon-pink disk.
Venus. is now getting closer to the Sun and nearing the end of its morning apparition. It will be just visible in the pre-dawn sky during the early part of the month but by months end will be lost in the glare of the Sun. As dawn breaks it will start the month at an elevation of ~10 degrees but this quickly reduces. During January its angular size drops from 10.8 to 10.1 arc seconds but, at the same time, the percentage illumination increases from 95 to 97% so the brightness does not change, remaining at -3.9 magnitudes.
See highlight above.
Find more planetary images and details about the Solar System: The Solar System
The Mid to Late Evening January Sky
This map shows the constellations seen in the south around midnight. The brilliant constellation of Orion is seen in the south. Moving up and to the right - following the line of the three stars of Orion's belt - brings one to Taurus; the head of the bull being outlined by the V-shaped cluster called the Hyades with its eye delineated by the orange red star Aldebaran. Further up to the right lies the Pleaides Cluster. Towards the zenith from Taurus lies the constellation Auriga, whose brightest star Capella will be nearly overhead. To the upper left of Orion lie the heavenly twins, or Gemini , their heads indicated by the two bright stars Castor and Pollux. Down to the lower left of Orion lies the brightest star in the northern sky, Sirius, in the consteallation Canis Major. Finally, up and to the left of Sirius is Procyon in Canis Minor. There is also information about the constellation Ursa Major, seen in the north,in the constellation details below.
The constellation Taurus
Taurus is one of the most beautiful constellations and you can almost imagine the Bull charging down to the left towards Orion. His face is delineated by the "V" shaped cluster of stars called the Hyades, his eye is the red giant star Aldebaran and the tips of his horns are shown by the stars beta and zeta Tauri. Although alpha Tauri, Aldebaran, appears to lie amongst the stars of the Hyades cluster it is, in fact, less than half their distance lying 68 light years away from us. It is around 40 times the diameter of our Sun and 100 times as bright.
To the upper right of Taurus lies the open cluster, M45, the Pleiades. Often called the Seven Sisters, it is one of the brightest and closest open clusters. The Pleiades cluster lies at a distance of 400 light years and contains over 3000 stars. The cluster, which is about 13 light years across, is moving towards the star Betelgeuse in Orion. Surrounding the brightest stars are seen blue reflection nebulae caused by reflected light from many small carbon grains. These relfection nebulae look blue as the dust grains scatter blue light more efficiently than red. The grains form part of a molecular cloud through which the cluster is currently passing. (Or, to be more precise, did 400 years ago!)
Close to the tip of the left hand horn lies the Crab Nebula, also called M1 as it is the first entry of Charles Messier's catalogue of nebulous objects. Lying 6500 light years from the Sun, it is the remains of a giant star that was seen to explode as a supernova in the year 1056. It may just be glimpsed with binoculars on a very clear dark night and a telescope will show it as a misty blur of light.
Its name "The Crab Nebula" was given to it by the Third Earl of Rosse who observed it with the 72 inch reflector at Birr Castle in County Offaly in central Ireland. As shown in the drawing above, it appeared to him rather lile a spider crab. The 72 inch was the world's largest telelescope for many years. At the heart of the Crab Nebula is a neutron star, the result of the collapse of the original star's core. Although only around 20 km in diameter it weighs more than our Sun and is spinning 30 times a second. Its rotating magnetic field generate beams of light and radio waves which sweep across the sky. As a result, a radio telescope will pick up very regular pulses of radiation and the object is thus also known a Pulsar. Its pulses are monitored each day at Jodrell Bank with a 13m radio telescope.
The constellation Orion
Orion, perhaps the most beautiful of constellations, will be seen in the south at around 11 - 12 pm during January. Orion is the hunter holding up a club and shield against the charge of Taurus, the Bull up and to his right. Alpha Orionis, or Betelgeuse, is a read supergiant star varying in size between three and four hundred times that of our Sun. The result is that its brightness varies somewhat. Beta Orionis, or Rigel, is a blue supergiant which, at around 1000 light years distance is about twice as far away as Betelgeuse. It has a 7th magnitude companion. The three stars of Orion's belt lie at a distance of around 1500 light years. Just below the lower left hand star lies a strip of nebulosity against which can be seen a pillar of dust in the shape of the chess-board knight. It is thus called the Horsehead Nebula. It shows up very well photographically but is exceedingly difficult to see visually - even with relativly large telescope.
Beneath the central star of the belt lies Orion's sword containing one of the most beautiful sights in the heavens - The Orion Nebula. It is a region of star formation and the reddish colour seen in photographs comes from Hydrogen excited by ultraviolet emitted from the very hot young stars that make up the Trapesium which is at its heart. The nebula, cradling the trapesium stars, is a beautiful sight in binoculars or, better still, a telescope. To the eye it appears greenish, not red, as the eye is much more sensitive to the green light emitted by ionized oxygen than the reddish glow from the hydrogen atoms.
The constellation Ursa Major
The stars of the Plough, shown linked by the thicker lines in the chart above, form one of the most recognised star patterns in the sky. Also called the Big Dipper, after the soup ladles used by farmer's wives in America to serve soup to the farm workers at lunchtime, it forms part of the Great Bear constellation - not quite so easy to make out! The stars Merak and Dubhe form the pointers which will lead you to the Pole Star, and hence find North. The stars Alcor and Mizar form a naked eye double which repays observation in a small telescope as Mizar is then shown to be an easily resolved double star. A fainter reddish star forms a triangle with Alcor and Mizar.
Ursa Major contains many interesting "deep sky" objects. The brightest, listed in Messier's Catalogue, are shown on the chart, but there are many fainter galaxies in the region too. In the upper right of the constellation are a pair of interacting galaxies M81 and M82 shown in the image below. M82 is undergoing a major burst of star formation and hence called a "starburst galaxy". They can be seen together using a low power eyepiece on a small telescope.
Another, and very beautiful, galaxy is M101 which looks rather like a pinwheel firework, hence its other name the Pinwheel Galaxy. It was discovered in1781 and was a late entry to Messier's calalogue of nebulous objects. It is a type Sc spiral galaxy seen face on which is at a distance of about 24 million light years. Type Sc galaxies have a relativly small nucleus and open spiral arms. With an overall diameter of 170,000 light it is one of the largest spirals known (the Milky Way has a diameter of ~ 130,000 light years).
Though just outside the constellation boundary, M51 lies close to Alkaid, the leftmost star of the Plough. Also called the Whirlpool Galaxy it is being deformed by the passage of the smaller galaxy on the left. This is now gravitationally captured by M51 and the two will eventually merge. M51 lies at a distance of about 37 million light years and was the first galaxy in which spiral arms were seen. It was discovered by Charles Messier in 1773 and the spiral structure was observed by Lord Rosse in 1845 using the 72" reflector at Birr Castle in Ireland - for many years the largest telescope in the world.
Lying close to Merak is the planetary nebula M97 which is usually called the Owl Nebula due to its resemblance to an owl's face with two large eyes. It was first called this by Lord Rosse who drew it in 1848 - as shown in the image below right. Planetary nebulae ar the remnants of stars similar in size to our Sun. When all possible nuclear fusion processes are complete, the central core collpses down into a "white dwarf" star and the the outer parts of the star are blown off to form the surrounding nebula.