C/2013 R1 (Lovejoy) is a non-periodic comet discovered on 7 September 2013 using a Schmidt–Cassegrain telescope. It is the fourth comet discovered by Terry Lovejoy. It crossed the celestial equator on 14 October 2013, which made it better observed from the Northern Hemisphere.
Observational history By 1 November 2013, the comet was visible to the naked eye near the Beehive Cluster (M44), about halfway between Jupiter and Regulus. It became more impressive than C/2012 S1 (ISON). In binoculars, the comet has the appearance of a green, unresolved globular cluster.
C/2013 R1 made its closest approach to Earth on 19 November 2013 at a distance of , and reached an apparent magnitude of about 4.5. On 27 November 2013 the comet was in the constellation of Canes Venatici, near the bottom of the handle of the Big Dipper. From 28 November until 4 December 2013, the comet was in the constellation Boötes. On 1 December 2013 it passed the star Beta Boötis. From 4 December until 12 December 2013, the comet was in the constellation Corona Borealis.
From 12 December until 14 January 2014, the comet was in the constellation Hercules. On 14 December 2013, it passed the star Zeta Herculis. The comet came to perihelion (closest approach to the Sun) on 22 December 2013 at a distance of from the Sun. At perihelion, the comet had an elongation of 51 degrees from the Sun. By September 2014, the comet had faded to magnitude 18.
Physical characteristics Chemical composition Narrow-band spectroscopy of the comet in December 2013 revealed that the coma of C/2013 R1 has a relatively high abundance in and molecules. Additional photometry from TRAPPIST until July 2014 determined that the detected organic compounds on its coma (OH, NH, CN, , and ) were partly caused by the breakdown of HCN outgassing from the comet.
Infrared observations from the Keck Observatory detected enriched amounts of CO, as well as hydrocarbons like , , and , indicating the variability of chemicals found in other Oort cloud comets. Other complex organic compounds, such as HCOOH, , and , were also detected from the comet.
Nucleus size and rotation The nucleus of C/2013 R1 is estimated to be about in radius, with a low bulk density of roughly about . Measurements of the dust emission structures around the comet determined that it has a rotation period about hours in length.
References
External links
C/2013 R1 at Seiichi Yoshida's website C/2013 R1 at Gary W. Kronk's Cometography
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