(Please note all times are UT and are based on an observing location of Belfast and covers the month of January)
At the start of the month, the Sun rises at 08:50 and sets at 16:10. By month's end, it rises at 08:15 and sets at 17:00.
22nd am Venus and Jupiter. The gap between the two will be around 2° with Venus to the North of Jupiter. They should hopefully be visible around 06:00.
Mercury is not easily visible this month and is superior conjunction on the 30th.
Venus is at greatest western elongation on the 6th and is a morning object this month. It is moving from Libra to Ophiuchus during the month. At the start of the month, it rises 04:40 and by month’s end, it rises at 05:35. It fades from mag -4.4 to mag -4.1 during the month.
Mars is visible in the evening sky in Pisces during the month. It sets at 23:35 and fades from mag +0.5 to mag +0.9 during the month.
Jupiter is a morning object this month in Ophiuchus. At the start of the month, it rises at 06:40 and by month’s end, it rises at 05:10. It brightens from mag -1.6 to mag -1.7 during the month.
Saturn is at conjunction on the 2nd and is not visible this month.
Uranus is an evening object in Pisces during the month. At the start of the month, it sets at 02:25 and by month’s end, it sets at 00:30. It maintains its brightness at mag +5.8 during the month and lies near to Omicron (ο) Piscium, mag +4.2.
Neptune is an evening object in Aquarius. At the start of the month, it sets at 21:55 and by month’s end, it sets at 20:05. It fades from mag +7.9 to mag +8.0 during the month. It lies between Phi (φ) Aquarii, mag +4.2 and Lambda (λ) Aquarii, mag +3.7.
The new moon is on the 6th (01:28) with the first quarter moon on the 14th (06:45). The full moon is on the 21st (05:16) with the last quarter moon on the 27th (21:10).
There is a total lunar eclipse in the wee hours of the 21st. It starts at 03:34 and runs through to 06:51. The total phase of the eclipse (when the moon is fully orange/red) is between 04:41 and 05:43.
1st am the 22% waning crescent lies NW of Venus at 05:00.
2nd am the 14% waning crescent lies SE of Venus at 05:00.
3rd am the 7% waning crescent lies N of Jupiter at 07:00.
10th pm the 18% waxing crescent lies S of Neptune at 17:00.
11th pm the 26% waxing crescent lies NE of Neptune at 17:00.
12th pm the 35% waxing crescent lies S of Mars at 17:00.
13th pm the 44% waxing crescent lies E of Mars at 17:00.
14th pm the 54% waxing gibbous lies SE of Uranus at 17:00.
16th pm the 74% waxing gibbous lies SW of M45 – The Pleiades at 17:00.
17th pm the 83% waxing gibbous lies N of Aldebaran (Alpha (α) Tauri, mag +0.9) at 17:00.
22nd pm the 96% waning gibbous lies N of Regulus (Alpha (α) Leonis, mag +1.4) at 20:00.
27th am the 59% waning gibbous lies E of Spica (Alpha (α) Virginis, mag +1.0) at 01:00.
31st am the 18% waning crescent lies SW of Venus and E of Jupiter at 06:00.
Feb 1st am the 11% waning crescent lies SE of Venus at 06:00.
The best time to observe meteor showers is when the moon is below the horizon; otherwise its bright glare limits the number you will see especially the fainter ones. Below is a guide to this month's showers.
The Quadrantids peak on the night of the 3rd/4th with a ZHR of 120. However the low position of the radiant makes a much lower ZHR more realistic. The radiant is roughly where the constellations Boötes, Draco and Hercules meet low in the North and is circumpolar. The meteors are of a medium speed – 42 km/s. The shower is named after a now defunct constellation Quadrans Mualis which lay between Boötes and Draco. Observing conditions are very good for the shower this year with new moon on the 6th.
There may be additional minor showers this month, details of which can be found in the below Information Sources and Links Section.
There are no bright asteroids at opposition this month.
Finder charts and further information about other fainter asteroids can be found in the below Information Sources and Links Section.
Comet 46P/Wirtanen peaked at mag +4 last month. It is currently mag +4 and is expected to fade in brightness. It will travel from Lynx to Ursa Major and will be visible all night during the month. It passes by Muscida (Omicron (ο) Ursa Majoris, mag +3.4) around the 11th. The diffuse nature of the comet will mean it will appear dimmer than its indicated brightness.
Comet 38P/Stephan-Oterma is predicted to remain at around mag +10 throughout January. It is currently mag +10 and is in Lynx during the month. It is visible all night during the month.
Finder charts and further information about the above and other fainter comets can be found in the below Information Sources and Links Section. Any of the above estimates are based on current information at the time of writing the guide and can be wrong - “Comets are like cats; they have tails, and they do precisely what they want”, David H Levy.
On the deep sky front this month, galaxies M81 and M82 can be observed in Ursa Major. In Andromeda, M31 - The Andromeda galaxy can be observed along with its satellite galaxies M32 and M110. In Perseus, there is the open cluster M34 and the excellent Double Cluster - NGC 869 and 884. In Triangulum, there is the galaxy M33. In Auriga there are three open clusters M36, M37 and M38 and also M35 in Gemini. Taurus has the excellent Pleiades - M45, the Hyades and also M1 - The Crab Nebula. Orion returns to our skies with M42 - The Great Orion Nebula and also Cancer with M44 - The Beehive Cluster.
Always keep an eye out for Aurorae. Other interesting naked eye phenomena to look out for include the Zodiacal Light and the Gegenschein. Both are caused by sunlight reflecting off dust particles which are present in the solar system.
The Zodiacal Light can be seen in the West after evening twilight has disappeared or in the East before the morning twilight. The best time of year to see the phenomenon is late-Feb to early-April in the evening sky and September/October in the morning sky - it's then that the ecliptic, along which the cone of the zodiacal light lies, is steepest in our skies. The Gegenschein can be seen in the area of the sky opposite the sun. To view either, you must get yourself to a very dark site to cut out the light pollution. When trying to observe either of these phenomena, it is best to do so when the moon is below the horizon. A new appendix has been added explaining some of the more technical terms used in the guide.
The ZHR or Zenithal Hourly Rate is the number of meteors an observer would see in one hour under a clear, dark sky with a limiting apparent magnitude of 6.5 and if the radiant of the shower were in the zenith. The rate that can effectively be seen is nearly always lower and decreases as the radiant is closer to the horizon. The Zenith is the overhead point in the sky.