Comet Catalina (C/2013 US10), discovered in October 2013 has been steadily moving inbound in our solar system toward perihelion (closest to the Sun) – which was this past November 15th. The comet is moving close to perpendicular to the plane of the ecliptic with an inclination of about 146o. This comet is a member of the Oort Cloud of icy objects that surround the solar system at great distances beyond Pluto. From such a distance a comet like this one has an orbital period that could be measured in the millions of years.
This comet, when discovered by the Catalina Sky Survey automated telescope, was at an apparent magnitude of 19, and the most recent images and observations show the comet to have brightened to around 7th magnitude as of this posting in August 2015. That puts it bright enough to be seen in darker skies with binoculars, however for viewing from the northern hemisphere the comet will not appear above the eastern horizon during night hours (actually early morning) until late November. As this graphic shows the comet will pass within less than 1o from the star Arcturus in Bootes the Herdsman on the mornings of December 31st and January 1st.
Unfortunately the waning phases of the Moon and its reflected light will brighten the sky and possibly interfering with some viewing.
During December, as this animated graphic shows, the comet moves higher above the horizon each day during December, although it will also be moving outbound and thus will get dimmer daily.The animated graphic is set for 6 am CST and starts on December 1st and ends on January 3rd
Looking for ‘Catalina’
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.