Comet 2013 US10 Catalina has been in the morning sky for northern observers since the start of December. Not that there's been much chance to see it! The weather here has been mostly appalling for much of that time.
For a few days around the New Year period Catalina will buzz past Arcturus - the brightest star in the northern sky. Arcturus is an orange giant star - there really is no mistaking it in high in the south east before dawn breaks. Arcturus provides an easy signpost to Comet Catalina as the year ends.
A clear transparent sky away from light pollution is essential to view the comet. It isn't quite bright enough to be visible without optical aid: binoculars or telescopes will easily show it.
Here is a closer view of the sky around Arcturus. The star and comet will appear closest together in the sky on New Year's morning.
A more detailed finder chart for the comet can be found here.
These long winter nights are perfect for stargazing! Here's a brief look at the astronomical highlights of this month.
The innermost planet Mercury puts in an appearance in the early evening sky. Look towards the southwest about 40 minutes after sunset during the first week or so of the month to catch a glimpse of it. Jupiter rises around midnight and shines brighter than any other star in the evening sky. For early risers the planet Mars – looking distinctly orange – can be found among the stars of Libra. Venus is drawing further in to the morning twilight but remains easy to find in the southeast sky just before dawn. Venus will be very close to Saturn on the morning of January 9th; Venus is much the brighter of the two planets.
The planet Uranus remains observable in the evening sky in the constellation Pisces. Binoculars are sufficient to see this distant ice giant but telescopes at moderate magnification are necessary to discern the green-blue disk.
Stars and constellations
Here is a star chart showing the evening sky in January. It is designed for my home in Northumberland but will good enough for observers throughout the UK.
The southern aspect of the night sky is dominated by the constellation Orion (the Hunter) which occupies the sky about halfway between the southern horizon and overhead. The most prominent feature of Orion is the "Belt" - three stars in a near straight line. There are many sights to see with binoculars and telescopes in Orion. The most famous is the great Orion Nebula which is to be found below the Belt stars, in Orion's Sword. The nebula is a stellar nursery and the region glows because of one or two particularly hot, young stars within it. The Orion nebula is merely the tip of the iceberg! The stars of Orion lie in the direction of numerous giant clouds of hydrogen - a very long exposure of the region shows many, many more objects than are visible to the naked eye.
Auriga, the Charioteer, is almost overhead and the leading star Capella is a yellowish star at a distance of 45 light-years. The Milky Way looks particularly rich as it flows from Perseus, through Auriga and towards Taurus, the Bull. Aldebaran is the brightest star in Taurus and is an orange giant at a distance of 65 light-years from us; it is bloated, orange giant star nearing the end of its life. Following a line from Orion's Belt down to the southeast horizon will lead you to Sirius, the brightest star in the entire sky. The brightness is not a true indication of true luminosity; Sirius is just under 9 light-years from us and although it is somewhat more powerful than the Sun, it is far less luminous than Rigel. Rising in the east is the Sickle-pattern of stars marking the head of Leo, the Lion.
Jan 01 --- Comet Catalina close to bright star Arcturus in the morning sky.
Jan 02 --- Last quarter moon
Jan 02 --- Moon at apogee (furthest from Earth); 251,206 miles (404,277 km).
Jan 02 --- Earth at perihelion (closest to Sun); 91.4 million miles (147 million km)
Jan 04 --- Quadrantid meteor shower peak
Jan 05 --- Pluto conjunction with Sun
Jan 07 --- Crescent moon near Venus and Saturn in morning sky.
Jan 09 --- Venus and Saturn conjunction (about 5 arcminutes apart; very close!)
Jan 10 --- New moon
Jan 10 --- Moon and Mercury conjunction (very difficult to observe!; SW horizon around 4.40pm)
Jan 14 --- Mercury inferior conjunction
Jan 15 --- Moon at perigee (closest to Earth); 229,391 miles (369,169 km)
Jan 16 --- First quarter moon
Jan 17 --- Comet Catalina closest to Earth (108 million km).
Jan 19 --- Gibbous moon in the Hyades star cluster
Jan 24 --- Full moon
Jan 27 --- Moon and Jupiter less than 2 degrees apart.
Jan 27 --- Asteroid 115 Thyra at opposition (mag. +9.9, in constellation Cancer)
Jan 30 --- Moon at apogee (furthest from Earth); 251,378 miles (404,553 km).
Quadrantid meteor shower
The last major meteor shower of the winter is expected to peak during the early hours of the morning of January 4th. The Quadrantid meteors radiate away from the border of the constellations Bootes and Hercules and it is named after a now defunct constellation – the Mural Quadrant. The peak in 2016 comes on the evening of January 3rd, with the best time to observe being the early hours of January 4th. During the narrow peak, rates as high as 120 meteors per hour might be possible. There will be some moonlight interference from a waning crescent moon.
A gallery of some of my favourite pictures of the universe!
This is almost becoming a Christmas tradition for me; an elongation chart for the bright planets in 2016:
A high quality PDF version with much more information can be downloaded here.
The planets shown are Mercury (m), Venus (V), Mars (M), Jupiter (J) and Saturn (S).
This chart shows the positions of each planet relative to the Sun (middle) all through the year. The vertical axis represents the days and months of the year. The diagonal bands represent constellation boundaries. The wavy yellow band is a region close to the Sun in which it would be difficult to observe the planets. The wavy yellow line represents regions of the sky rendered invisible because of the proximity of the Sun. The shape of that wavy line explains, for example, why Mercury is easier to observe in the October morning sky than the September morning sky (even though it is further from the Sun in September). Also, the chart behaves like a game of PacMan; any planets reaching opposition 180 degrees west of the Sun wrap straight over to the evening sky on the far left. Think of this as being like an unwrapped cylinder!
Places where the lines intersect planetary conjunctions --- often beautiful (but not significant) events where the planets appear close together in the sky. There will be several notable conjunctions from August through to November 2016. Here are details of all the conjunctions potentially observable from the UK.
The numbers in the first column refer to the numbered conjunctions on the elongation chart.
Finally, the elongation chart was compiled in LaTeX and PSTricks using data from the JPL Planetary Dynamics website.
Dr Adrian Jannetta
Guitar strummin' explorer of the universe. Mild mannered maths teacher by day and astronomer by night.