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Comet Catalina is now well placed for observation in the morning sky for observers at Northern Hemisphere latitudes. For the last few months the comet has been brighter than 7th magnitude and therefore within the range of binoculars and small scopes. Catalina hasn't quite reached naked eye brightness and now seems unlikely to make it, but even so it should remain at this brightness level for a number of weeks to come. Visually it shows a small faint tail of a degree in length. Photographically the comet looks superb.

Comet Catalina (credit - Ian Sharp/Siding Spring Observatory Australia)

Location and star charts

From mid-northern latitudes, Catalina is observable at the end of December from about 2am local time as it continues on its almost direct northwards path. On January 1st it passes less than one degree west of bright orange star Arcturus (mag. -0.04). The close proximity to Arcturus is a mixed blessing; the advantage easy to find the comet, the disadvantage the comet is vastly overpowered in brightness by the star. For comparison, Arcturus is 250x the brighter of the pair. Of course in reality, Catalina is nowhere near Arcturus with the star a few million more times distant!

On January 17th, Catalina makes its second and last flyby of Earth. On this day it approaches to within 0.72 AU or 108 million kilometres (67 million miles) of our planet and is predicted to shine at magnitude +6.2. It will be amongst the stars of Ursa Major. After this the comet will gradually fade in brightness although at the same time from northern latitudes appearing higher in the sky. From southern latitudes it's hardly observable anymore.

The finder charts below show the positions of Catalina from December 18, 2015 to January 10, 2016.

Comet Catalina at about 2am from mid northern temperate latitudes on January 7, 2016 (credit:- Stellarium)

Comet Catalina (C/2013 US10) Finder Chart from January 1st to January 10th, 2016 (credit:- freestarcharts)

Comet Catalina (C/2013 US10) Finder Chart from January 1st to January 10th, 2016 - pdf format (credit:- freestarcharts)

Comet Catalina (C/2013 US10) Finder Chart from December 18th, 2015 to January 1st, 2016 (credit:- freestarcharts)

Comet Comet Catalina (C/2013 US10) Finder Chart from December 18th, 2015 to January 1st, 2016 - pdf format (credit:- freestarcharts)

C/2013 US10 (Catalina) Data (at epoch November 15, 2014)

NameC/2013 US10 (Catalina)
DiscovererCatalina Sky Survey
Discovery dateOctober 31, 2013
Perihelion (AU)0.82290
Orbital period (years)unknown
Inclination (degrees) 148.8733
Longitude of ascending node (degrees)186.1371
Perihelion November 15th, 2015

(C2013/US10) Catalina Data Table

16-Dec-201514h 17m 34s-01d 02m 34s6.71.234Virgo
17-Dec-201514h 17m 28s-00d 09m 36s6.71.212Virgo
18-Dec-201514h 17m 22s00d 45m 20s6.61.190Virgo
19-Dec-201514h 17m 15s01d 42m 21s6.61.168Virgo
20-Dec-201514h 17m 08s02d 41m 35s6.61.147Virgo
21-Dec-201514h 17m 00s03d 43m 10s6.61.125Virgo
22-Dec-201514h 16m 52s04d 47m 15s6.51.103Virgo
23-Dec-201514h 16m 42s05d 53m 59s6.51.082Virgo
24-Dec-201514h 16m 31s07d 03m 32s6.51.060Virgo
25-Dec-201514h 16m 19s08d 16m 03s6.51.039Boötes
26-Dec-201514h 16m 05s09d 31m 44s6.51.018Boötes
27-Dec-201514h 15m 50s10d 50m 43s6.40.997Boötes
28-Dec-201514h 15m 33s12d 13m 14s6.40.976Boötes
29-Dec-201514h 15m 13s13d 39m 25s6.40.956Boötes
30-Dec-201514h 14m 52s15d 09m 29s6.40.936Boötes
31-Dec-201514h 14m 27s16d 43m 35s6.40.917Boötes
01-Jan-201614h 13m 59s18d 21m 48s6.40.898Boötes
02-Jan-201614h 13m 28s20d 04m 29s6.40.880Boötes
03-Jan-201614h 12m 53s21d 51m 41s6.40.863Boötes
04-Jan-201614h 12m 13s23d 43m 30s6.30.846Boötes
05-Jan-201614h 11m 28s25d 40m 01s6.30.830Boötes
06-Jan-201614h 10m 37s27d 41m 18s6.30.815Boötes
07-Jan-201614h 09m 40s29d 47m 20s6.30.800Boötes
08-Jan-201614h 08m 35s31d 58m 03s6.30.787Boötes
09-Jan-201614h 07m 22s34d 13m 22s6.30.775Canes Venatici
10-Jan-201614h 05m 59s36d 33m 03s6.30.764Canes Venatici
11-Jan-201614h 04m 24s38d 56m 52s6.30.754Canes Venatici
12-Jan-201614h 02m 36s41d 24m 25s6.30.746Canes Venatici
13-Jan-201614h 00m 32s43d 55m 16s6.30.738Canes Venatici
14-Jan-201613h 58m 11s46d 28m 54s6.30.733Canes Venatici
15-Jan-201613h 55m 28s49d 04m 41s6.30.729Ursa Major
16-Jan-201613h 52m 21s51d 41m 54s6.20.726Ursa Major
17-Jan-201613h 48m 43s54d 19m 49s6.20.725Ursa Major
18-Jan-201613h 44m 28s56d 57m 34s6.20.725Ursa Major
19-Jan-201613h 39m 30s59d 34m 18s6.30.727Ursa Major
20-Jan-201613h 33m 36s62d 09m 04s6.30.731Ursa Major
21-Jan-201613h 26m 34s64d 40m 54s6.40.736Draco
22-Jan-201613h 18m 05s67d 08m 46s6.40.743Draco
23-Jan-201613h 07m 46s69d 31m 34s6.50.751Ursa Minor
24-Jan-201612h 55m 03s71d 48m 02s6.50.761Draco
25-Jan-201612h 39m 12s73d 56m 43s6.60.772Draco
26-Jan-201612h 19m 14s75d 55m 44s6.70.785Draco
27-Jan-201611h 53m 53s77d 42m 41s6.70.799Camelopardalis
28-Jan-201611h 21m 47s79d 14m 21s6.70.814Draco
29-Jan-201610h 41m 53s80d 26m 41s6.80.830Draco
30-Jan-201609h 54m 33s81d 15m 18s6.80.848Draco
31-Jan-201609h 02m 43s81d 37m 01s6.90.866Camelopardalis

See also

Comet Catalina (C/2013 US10) moves past Kemble's Cascade during the last week of February 2016. Visible with binoculars and small telescopes from northern and tropical latitudes.
Comet Catalina (C/2013 US10) now fading as it recedes from Earth. Currently moving through the far northern constellations. Remains visible with binoculars and small telescopes.
Comet Catalina (C/2013 US10) remains visible with binoculars and small telescopes at it moves northwards. This month offers the last good chance to catch a glimpse before it fades significantly.
Comet Catalina (C/2013 US10) remains an early morning binocular and small telescope object
Catalina (C/2013 US10) an early morning binocular and small telescope comet
Comet Catalina (C/2013 US10) edges towards naked eye visibility
Comet Catalina (C/2013 US10) remains visible in the evening from Southern and Equatorial Latitudes during September 2015
Comet Catalina (C/2013 US10) now visible with binoculars from Southern and Equatorial Latitudes