Ultraviolet observations of Chiron with the HST/FOS: Examining a Centaur's Gray Matter

Details Ultraviolet observations of Chiron with the HST/FOS: Examining a Centaur's Gray Matter Ultraviolet observations of Chiron with the HST/FOS: Examining a Centaur's Gray Matter

May 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997aj....113.1899p&link_type=abstract

Astronomical Journal v.113, p. 1899-1908 (1997)

Astronomy and Astrophysics

Astronomy

6

Scientific paper

We present ultraviolet (UV) observations of Chiron during two epochs using the Hubble Space Telescope / Faint Object Spectrograph (HST/FOS). The first observations (1996 Jan 23-24 UT) were made 3 weeks before Chiron's perihelion, and include a series of seven spectra obtained over 3.9 hours. A single follow-up observation was made 3 months later (1996 Apr 13 UT). We used these data to study flux variations and set upper limits on selected coma abundances. The most intriguing result of our observations is that Chiron's UV continuum flux in April was 60% higher than expected from the January flux. The source of this significant increase is unknown, but may be tantalizing evidence of: a highly unusual phase function; recoating of the surface from an unobserved outburst; or a cold, persistent, near-surface ``fog'' (small scale height atmosphere) that experienced a peculiar, unresolved outburst. Chiron was characteristically gray in the UV (2600-3300 Angstroms) in January 1996, with an average geometric albedo of 0.076 +/- 0.003 (assuming a radius of 90km) and displayed no detectable UV color variations with rotational phase. In the April 1996 data, the average UV geometric albedo was 0.109 +/- 0.007, and we detect evidence for a blue color, which may be connected to the observed flux increase. During the January of observations, Chiron's UV lightcurve had a peak-to-peak variation of 7%, similar to that of the visible lightcurve. We found no evidence of coma emissions, and use the April data to set 3sigma upper limits to the column abundances of N(CS lambda 2576) < 4.3xten {13}cm(-2) and N(OH lambda 3085) < 1.5xten {14}cm(-2) .

Affiliated with

Also associated with

No associations

Rating

Ultraviolet observations of Chiron with the HST/FOS: Examining a Centaur's Gray Matter does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ultraviolet observations of Chiron with the HST/FOS: Examining a Centaur's Gray Matter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultraviolet observations of Chiron with the HST/FOS: Examining a Centaur's Gray Matter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-835740