Astrometric Jitter of the Sun as a Star
- Creators
- Makarov, V. V.
- Parker, D.
- Ulrich, R. K.
Abstract
The daily variation of the solar photocenter over some 11 yr is derived from the Mount Wilson data reprocessed by Ulrich et al. to closely match the surface distribution of solar irradiance. The standard deviations of astrometric jitter are 0.52 μAU and 0.39 μAU in the equatorial and the axial dimensions, respectively. The overall dispersion is strongly correlated with solar cycle, reaching 0.91 μAU at maximum activity in 2000. The largest short-term deviations from the running average (up to 2.6 μAU) occur when a group of large spots happen to lie on one side with respect to the center of the disk. The amplitude spectrum of the photocenter variations never exceeds 0.033 μAU for the range of periods 0.6-1.4 yr, corresponding to the orbital periods of planets in the habitable zone. Astrometric detection of Earth-like planets around stars as quiet as the Sun is not affected by star spot noise, but the prospects for more active stars may be limited to giant planets.
Additional Information
© 2010 American Astronomical Society. Received 2010 February 26; accepted 2010 May 19; published 2010 June 23. The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Observations at the 150 ft telescope on Mount Wilson have been supported over the years by grants from the National Aeronautics and Space Administration, the National Science Foundation (NSF), and Office of Naval Research. Research is currently supported by the NSF through grant AGS-0958779.Attached Files
Published - Makarov2010p11127Astrophys_J.pdf
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Additional details
- Eprint ID
- 19642
- Resolver ID
- CaltechAUTHORS:20100824-132119000
- NASA
- Created
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2010-08-25Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field