Photometric observations of asteroid 4 Vesta by the OSIRIS cameras onboard the Rosetta spacecraft

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

2

Minor Planets, Asteroids: Individual: 4 Vesta, Techniques: Photometric

Scientific paper

Aims: We report on new observations of asteroid 4 Vesta obtained on 1 May 2010 with the optical system OSIRIS onboard the ESA Rosetta mission. One lightcurve was taken at a phase angle (52°) larger than achievable from ground-based observations together with a spectrophotometric sequence covering the 260 to 990 nm wavelength range. Methods: Aperture photometry was used to derive the Vesta flux at several wavelengths. A Fourier analysis and the HG system formalism were applied to derive the Vesta rotational period and characterize its phase function. Results: We find a G parameter value of 0.27 ± 0.01 and an absolute magnitude H(R) = 2.80 ± 0.01. The lightcurve has the largest amplitude ever reported for Vesta (0.19 ± 0.01 mag), and we derive a synodic rotational period of 5.355 ± 0.025 h. The Rosetta spectrophotometry, covering the Vesta western hemisphere, is in perfect agreement with visible spectra from the literature and close to the IUE observations related to the same hemisphere. The new spectrophotometric data reveal that there is no global ultraviolet/visible reversal on Vesta. The Vesta spectrophotometry is well reproduced by spectra of howardite meteorite powders (grain size < 25 μm). From the Rosetta absolute spectrophotometry and from the phase function behaviour, we estimate a geometric albedo of 0.36 ± 0.02 at 649 nm and 0.34 ± 0.02 at 535 nm.
Table 2 is available in electronic form at http://www.aanda.org

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Photometric observations of asteroid 4 Vesta by the OSIRIS cameras onboard the Rosetta 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 Photometric observations of asteroid 4 Vesta by the OSIRIS cameras onboard the Rosetta spacecraft, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photometric observations of asteroid 4 Vesta by the OSIRIS cameras onboard the Rosetta spacecraft will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1077390

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.