Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-11T07:34:40.508Z Has data issue: false hasContentIssue false
  • English
  • Français

Perspective acceleration and gravitational redshift. Measuring masses of individual white dwarfs using Gaia + SIM astrometry

Published online by Cambridge University Press:  06 January 2010

Guillem Anglada-Escudé  and
John Debes
Guillem Anglada-Escudé
Affiliation:
Dept. of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Rd. Washington DC 20008, USA, email: anglada@dtm.ciw.edu
John Debes
Affiliation:
Goddard Space Flight Center, NASA Postdoctoral Program Greenbelt, Maryland 20771, USA email: john.h.debes@nasa.gov
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

According to current plans, the SIM/NASA mission will be launched just after the end of operations for the Gaia/ESA mission. This is a new situation which enables long term astrometric projects that could not be achieved by either mission alone. Using the well-known perspective acceleration effect on astrometric measurements, the true heliocentric radial velocity of a nearby star can be measured with great precision if the time baseline of the astrometric measurements is long enough. Since white dwarfs are compact objects, the gravitational redshift can be quite large (40–80 km/s), and is the predominant source of any shift in wavelength. The mismatch of the true radial velocity with the spectroscopic shift thus leads to a direct measure of the Mass–Radius relation for such objects. Using available catalog information about the known nearby white dwarfs, we estimate how many masses/gravitational redshift measurements can be obtained with an accuracy better than 2%. Nearby white dwarfs are relatively faint objects (10 < V < 15), which can be easily observed by both missions. We also briefly discuss how the presence of a long period planet can mask the astrometric signal of perspective acceleration.

Keywords

astrometry(stars:) white dwarfsrelativitystars: fundamental parameters(masses)
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 5 , Symposium S261: Relativity in Fundamental Astronomy: Dynamics, Reference Frames, and Data Analysis , April 2009 , pp. 342 - 344
Copyright
Copyright © International Astronomical Union 2010

References

Anglada-Escudé, G. & Torra, J. 2006, A&A, 449, 1281Google Scholar
Davis, D. S., Richer, H. B., King, I. R. et al. 2008, MNRAS, 383, L20CrossRefGoogle Scholar
Debes, J. H. & Sigurdsson, S. 2002, ApJ, 572, 556CrossRefGoogle Scholar
Dravins, D., Lindegren, L., & Madsen, S. 1999, A&A, 348, 1040Google Scholar
Gatewood, G. & Russell, J. 1974, AJ, 79, 815CrossRefGoogle Scholar
Holberg, J. B., Bergeron, P., & Gianninas, A. 2008a, AJ, 135, 1239CrossRefGoogle Scholar
Holberg, J. B., Sion, E. M., Oswalt, T. et al. 2008b, AJ, 135, 1225CrossRefGoogle Scholar
Villaver, E. & Livio, M. 2007, ApJ, 661, 1192CrossRefGoogle Scholar