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Astrometric detection of exo-Earths in the presence of stellar noise

Catanzarite, Joseph and Law, Nicholas and Shao, Michael (2008) Astrometric detection of exo-Earths in the presence of stellar noise. In: Optical and Infrared Interferometry. Proceedings of SPIE. No.7013. Society of Photo-Optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 70132K. ISBN 9780819472236.

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Astrometry from space is capable of making extremely precise measurements of the positions of stars, at angular precision of well below 1 micro-arcsecond (uas) at each visit. Hundreds of visits over a period of five years could achieve a relative astrometric precision for the mission of below 0.05 uas; this is well below the astrometric signature of 0.3 uas for a Sun-Earth system at a distance of 10 pc. The Sun's photometric fluctuations on time scales from days to years are dominated by the rotation and evolution of stellar surface features (sunspots and faculae). This flux variability is a source of astrophysical noise in astrometric as well as radial velocity (RV) measurements of the star. In this paper we describe a dynamic starspot model that produces flux variability which is consistent with the measured photometric power spectra of the Sun and several other stars. We use that model to predict the jitter in astrometric and RV measurements due to starspots. We also employ empirical stellar activity models to estimate the astrometric jitter of a much larger sample of stars. The conclusion of these simulations is that astrometric detection of planets in the habitable zones of solar-type stars is not severely impacted by the noise due to starspots/faculae, down to well below one Earth mass.

Item Type:Book Section
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Law, Nicholas0000-0001-9380-6457
Additional Information:© 2008 Society of Photo-Optical Instrumentation Engineers (SPIE). This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.
Funding AgencyGrant Number
Subject Keywords:astrometry, planet detection, radial velocity, starspots, sunspots
Series Name:Proceedings of SPIE
Issue or Number:7013
Record Number:CaltechAUTHORS:20190715-145507077
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Official Citation:Joseph Catanzarite, Nicholas Law, and Michael Shao "Astrometric detection of exo-Earths in the presence of stellar noise", Proc. SPIE 7013, Optical and Infrared Interferometry, 70132K (28 July 2008);
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:97153
Deposited By: Tony Diaz
Deposited On:15 Jul 2019 22:18
Last Modified:16 Nov 2021 17:27

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