DPS 35th Meeting, 1-6 September 2003
Session 28. Comets II: Gas Species
Oral, Chairs: S. Wyckoff and N. Biver, Thursday, September 4, 2003, 4:30-5:40pm, DeAnza III

[Previous] | [Session 28] | [Next]

[28.03] On the N2+/CO+ Ratio in Comet C/1995O1 (Hale-Bopp)

S. Wyckoff, R. S. Heyd (Arizona State University)

The nitrogen abundance in comets is critical for understanding conditions in the early solar nebula. Most models predict a relatively high nitrogen abundance in the outer solar nebula and in comets, with most of the volatile nitrogen in the form of N2. The N2+ B-X 0-0 band at 3914 A was identified in comet spectra nearly a century ago, but its identification in recent bright comets has proven difficult. Here we report a feature at 3914 A that we identify with the N2+ B-X 0-0 band in a tail spectrum (resolution 2500) of comet Hale-Bopp on April 13, 1997. If this band is N2+, then we find an N2+/CO+ ratio of the same order as values found in comets 1P/1982 U1 (Halley) and C/1987 P1 (Bradfield). If the dynamics of N2+ and CO+ were comparable in comet Hale-Bopp then the volatile N2/CO ratio inferred in comet Hale-Bopp is much smaller than most model predictions.

The author(s) of this abstract have provided an email address for comments about the abstract: wyckoff@asu.edu

[Previous] | [Session 28] | [Next]

Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.