Comet Catalina 2013 US10
Comet Catalina is an Oort cloud comet discovered on 31 October 2013 by the Catalina Sky Survey
at an apparent magnitude of 19 using a 0.68-meter (27 in) Schmidt–Cassegrain telescope.
As of September 2015 the comet is around apparent 6th magnitude.
When discovered on 31 October 2013 observations from another object from 12 September 2013 were used
in the preliminary orbit determination giving an incorrect solution that suggested an orbital period of only 6 years.
But by 6 November 2013 a longer observation arc from 14 August until 4 November
made it apparent that the first solution had the wrong object from 12 September.
By early May 2015 the comet was around apparent magnitude 12 and had an elongation of 60 degrees
from the Sun as it moved further into the southern hemisphere.
The comet came to solar conjunction on 6 November 2015 when the comet was around magnitude 6.
The comet came to perihelion (closest approach to the Sun) on 15 November 2015
at a distance of 0.82 AU from the Sun At perihelion,
It had a velocity of 46.4 km/s (104,000 mph) with respect to the Sun which is slightly greater than the Sun's escape velocity at that distance.
It crossed the celestial equator on 17 December 2015 becoming a northern hemisphere object.
On 17 January 2016 the comet will pass 0.72 AU (108,000,000 km; 67,000,000 mi) from Earth
and should be around magnitude 6 while located in the constellation of Ursa Major
C/2013 US10 is dynamically new.
It came from the Oort cloud with a loosely bound chaotic orbit that was easily perturbed by galactic tides and passing stars.
Before entering the planetary region (epoch 1950),
C/2013 US10 had an orbital period of several million years.
leaving the planetary region (epoch 2050), it will be on an ejection trajectory.
never got a decent image of Comet Catalina.
The image below was
my best effort. Long hours at work and a particularly bad winter
conspired to keep the comet from my site on every except this one
when I got a couple of quick glimpses of the comet, but no
On November 30th, 2015 I Saw Comet Catalina (C2013 US10)in the morning sky, way down in the gunk, near the horizon.
a line from Venus towards the horizon following the ecliptic. No hint
of a tail in the binocs, but the diffuse green fuzzball was
It's just on the borderline of being visible, being so low and in the soup at 5:15am.
You might want to try looking at ~6am, when it is still relatively dark and up out of the muck a bit....
finally got a glimpse of Catalina. I went to the Wellington Fairgrounds
Overflow Parking lot, used only during the Wellington, Ohio's annual
The rest of the year it is a huge hundred acre field
that sits empty. The comet is faint, but you can see it upper left in
the photo below.