Observations of Mercury's Anti-Sunward Emissions by the STEREO Spacecraft

Details Observations of Mercury's Anti-Sunward Emissions by the STEREO Spacecraft Observations of Mercury's Anti-Sunward Emissions by the STEREO Spacecraft

Oct 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010dps....42.2105s&link_type=abstract

American Astronomical Society, DPS meeting #42, #21.05; Bulletin of the American Astronomical Society, Vol. 42, p.986

Astronomy and Astrophysics

Astronomy

Scientific paper

Heliospheric Imagers HI-1 aboard both the STEREO-A (Ahead) and -B (Behind) spacecraft occasionally record emissions extending anti-sunward in a tail from Mercury. HI-1A measurements on 28 January 2009 show a sustained brightness of nearly 30 kilo-Rayleighs over more than 24 hours at a distance of 12 arcminutes from the planet. At this time, the line of sight from STEREO-A and the Sun-Mercury directions differs by only 7 degrees, with the tail pointed toward the Ahead spacecraft. Correcting for path length and projection, this corresponds to a cross-tail brightness of 7 kiloRayleighs at a physical distance of nearly 430 planetary radii. A sodium tail has been observed from the ground at such distances, with a typical brightness between 100 and 200 Rayleighs for similar orbital phases. The transmission of sodium D line wavelengths though the broadband filters in HI-1 is between 1 and 2 percent. It is unlikely that the HI-1A recorded emissions in the kR range would be due to sodium at such distances. Thomson scattering of sunlight from nearby solar coronal electrons is seen simultaneously throughout the HI-1 field with short-term brightness variations near Mercury. Whether the tail feature observed is due to solar wind electrons or scattering off dust particles remains to be determined. The STEREO space-based observing capability provides new insights into long and short-term temporal variability in the Hermean system and its potential sources.

Affiliated with

Also associated with

No associations

Rating

Observations of Mercury's Anti-Sunward Emissions by the STEREO Spacecraft 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 Observations of Mercury's Anti-Sunward Emissions by the STEREO Spacecraft, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observations of Mercury's Anti-Sunward Emissions by the STEREO Spacecraft will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1122159