DPS 2001 meeting, November 2001
Session 46. Cometary Atmospheres and Solar Wind Interaction
Oral, Chairs: M. Hanner, A. Levasseur-Regourd, Friday, November 30, 2001, 3:00-4:10pm, Regency E

[Previous] | [Session 46] | [Next]

[46.01] Latest Results from SOHO/LASCO Observations of Kreutz Family Comets

D.A. Biesecker (Emergent-IT Inc., NASA/GSFC), P.L. Lamy (LAS-Marseille), O.C. St. Cyr (Catholic Univ, NRL, NASA/GSFC), A. Llebaria (LAS-Marseille), R.A. Howard (Naval Research Laboratory)

As of September 2001, almost 350 members of the Kreutz sungrazing comet family have been observed with the LASCO coronagraphs on SOHO. The lightcurves of many of these comets share common features. They all reach a peak brightness at a heliocentric distance of about 12 solar radii (0.056 AU), then fade as they approach closer to the Sun, down to a distance of 7 solar radii where the fading stops. A closer examination reveals that two groups can be distinguished, one which peaks at 11.2 solar radii and one at 12.3 solar radii. Observations through an `Orange' filter (5400-6400 Angstroms) are systematically brighter than those through a `Clear' filter (4000-9000 Angstroms) and the difference changes with heliocentric distance. Recently, high cadence observations with other color filters have shown that the enhancement is limited to the Orange and Clear filters. This supports our idea that Na emission is a likely candidate for the enhancement. We will present these observations as well as our latest ideas to explain the LASCO observations.

The author(s) of this abstract have provided an email address for comments about the abstract: doug@sungrazer.nascom.nasa.gov

[Previous] | [Session 46] | [Next]