C/2013 UQ4 (Catalina)
A comet discovered as an asteroid, later confirmed by diffuse appearance.
C/2013 UQ4 (Catalina) is a Solar System comet that was initially discovered as an asteroid-like object before being identified as a comet. It is notable for its close approach to Earth in July 2014 and for being observed by the NEOWISE mission.
Quick Facts
- Discoverer
- Catalina Sky Survey
- Discovery Date
- 23 October 2013
- Epoch
- 12 July 2014
- Observation Arc
- 862 days
- Aphelion
- 120.06 AU
- Perihelion
- 1.081 AU
- Semimajor
- 60.57 AU
- Eccentricity
- 0.982
- Period
- 471 years
- Inclination
- 145.26°
- Asc Node
- 317.66°
- Arg Peri
- 23.31°
Facts from the source article.
Lore & Background
The object was discovered on October 23, 2013, by the Catalina Sky Survey in Arizona, United States, with an estimated apparent magnitude around 18.5. It had an asteroid-like appearance but a comet-like orbit, and was initially named 2013 UQ4. On April 26, 2014, astronomer Michael Mattiazzo observed the object to be slightly diffuse in two-minute exposures obtained with a Canon EOS 5D Mark II and a 400mm f/2.8 lens. On May 7, 2014, astronomers A. Novichonok and T. Prystavski noticed a fuzzy, coma-like aspect, revealing it was indeed a comet (with total brightness 13.5 mag and coma diameter of 1.5'). The object was then given the comet designation C/2013 UQ4 (Catalina).
The comet reached its perihelion on June 5, 2014, and its perigee on July 10, 2014, at a distance of about 47 million kilometers. It peaked around apparent magnitude 9 and was visible in small telescopes. The comet was also observed by the NEOWISE mission on July 7, 2014, in the infrared, and was noted to have a tail measuring 100,000 kilometers in length. From late July 2014 until March 2015, as seen from Earth, the comet appeared near Arcturus.
Reader's Guide
C/2013 UQ4 (Catalina) is significant as an example of an object initially misidentified as an asteroid due to its appearance, but later confirmed as a comet through observations of its diffuse coma. Its discovery and reclassification highlight the importance of follow-up observations by both amateur and professional astronomers. The comet's close approach to Earth on July 10, 2014, at a distance of 0.314 AU, allowed it to reach a peak apparent magnitude of 9, making it observable in small telescopes. The observation by the NEOWISE mission on July 7, 2014, provided infrared data and revealed a tail 100,000 kilometers long. The comet's visibility near the bright star Arcturus from late July 2014 until March 2015 offered a convenient reference point for observers. Its legacy lies in demonstrating the dynamic nature of small Solar System bodies and the collaborative effort required to characterize them.
Did You Know?
- It was initially named 2013 UQ4 before being reclassified as a comet on May 7, 2014.
- The comet's tail was measured at 100,000 kilometers long by the NEOWISE mission.
- From late July 2014 until March 2015, the comet appeared near the star Arcturus.
Frequently Asked Questions
What is C/2013 UQ4 (Catalina)?
It is a Solar System comet that was first catalogued as an asteroid-like body before its true nature was confirmed. The object was spotted by the Catalina Sky Survey in Arizona and later observed by NASA's NEOWISE mission.
When and where was C/2013 UQ4 (Catalina) discovered?
The object was first detected on October 23, 2013, by the Catalina Sky Survey in Arizona, United States. At that time it appeared as a faint point source with an apparent magnitude of about 18.5.
How did C/2013 UQ4 (Catalina) go from asteroid to comet?
Initial observations showed a solid, asteroid-like silhouette, so it was tracked as a minor planet. By May 7, 2014, astronomers noticed a diffuse, fuzzy tail-like structure around the nucleus, prompting its reclassification as a comet.
When did C/2013 UQ4 (Catalina) pass closest to Earth and the Sun?
The comet reached perihelion—its nearest point to the Sun—on June 5, 2014, and then swung past Earth at perigee on July 10, 2014. That July flyby made it a target of interest for the NEOWISE infrared survey.
Why is C/2013 UQ4 (Catalina) notable among named comets?
Its story stands out because it was initially misidentified as a rocky asteroid before the development of a visible coma revealed its cometary identity. The roughly seven-month gap between discovery and formal comet designation makes it a good example of how near-Earth objects can be misclassified.
More in Named Comets, Part 3 1-24
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