C/2001 HT50 (LINEAR-NEAT)

C/2001 HT50 (LINEAR-NEAT) is one of the many comets that have been discovered over the last few years by automated search programmes as a presumed asteroid and later seen to be active. It was identified as an 18th magnitude object on images taken with the 1.2-m Schmidt at Mount Palomar on May 14th 2001, within the NEAT programme. Tim Spahr immediately realised that the same object had been detected by LINEAR on April 23rd and LONEOS on April 26th and reported as an asteroid that was designated 2001 HT50. Further investigation showed that it had also previously been observed by LINEAR on March 3rd and by the 1.2-m NEAT at Haleakala (Hawaii) on March 21st.

This object proved to be an interesting test case for the naming system for comets. Priority was given in the naming to the team that had reported the object 2001 HT50 with which the comet was identified (LINEAR) and to the team that had recognised the object as being a comet (NEAT). In most cases the identifier of cometary activity would not be credited as a co-discoverer because the object was already a suspect comet. The NEAT observations though represented a genuine independent discovery of the comet. Such cases are decided on their merits on an individual basis by the Small Bodies Naming Committee of the IAU which is the final arbiter of how a comet's discovery should be credited.

The comet was discovered two years from perihelion. C/2001 HT50 (LINEAR-NEAT) will reach perihelion at 2.79AU from the Sun on July 9th 2003 and will be close to opposition at the time making it very favourably placed for observation. At this time it may reach magnitude 11. The comet has a retrograde orbit of very long period.

The light curve

The light curve shows the comet brightening rapidly during 2002. Some visual estimates from Japan suggest that the comet may be much brighter than indicated here and indicate that the total magnitude may reach 9.

When the comet emerged from conjunction in October 2002 it was still almost 4AU from the Sun and its brightness gave an indication of just how bright the comet should become. At present it seems that magnitude 11-12 is likely to be the peak.

Recent observations though seem to suggest that the comet is suffered a significant outburst at the end of 2002 in the 10 arcsecond aperture which reflects a sudden large increase in gas activity from the innermost coma.

The light curve on an expanded scale suggests that there was a broad maximum in the light curve from late December 2002 to early March 2003, although only the step up in brightness is clear from the data.

 CCD observation in a 10 arcsecond aperture by:

CCD aperture photometry in apertures of 20", 30", 40", 0'.9 and 1'.0 by:

Total visual magnitude estimates by:

 

Última actualización 22/05/2003
Por M.R.Kidger