Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-10T13:31:58.072Z Has data issue: false hasContentIssue false
  • English
  • Français

Micro-arcsecond relative astrometry by ground-based and single-aperture observations

Published online by Cambridge University Press:  01 October 2007

T. Röll ,
A. Seifahrt  and
R. Neuhäuser
T. Röll
Affiliation:
Astrophysikalisches Institut und Universitäts-Sternwarte Jena, email: troell@astro.uni-jena.de, rne@astro.uni-jena.de
A. Seifahrt
Affiliation:
Astrophysikalisches Institut und Universitäts-Sternwarte Jena, email: troell@astro.uni-jena.de, rne@astro.uni-jena.de Institut für Astrophysik, Göttingen email: seifahrt@astro.physik.uni-goettingen.de
R. Neuhäuser
Affiliation:
Astrophysikalisches Institut und Universitäts-Sternwarte Jena, email: troell@astro.uni-jena.de, rne@astro.uni-jena.de
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.

We present an observation method to obtain a relative astrometric precision of about 100 . . . 150 μas with ground-based and single-aperture observations. By measuring the separation of double or triple stars we want to determine the astrometric signal of an unseen substellar companion as a periodic change in the separation between the stellar components. Using an adaptive optics system we correct for atmospheric turbulences and furthermore by using a narrow band filter in the near infrared we can suppress differential chromatic refraction effects. To reach a high precision we use a statistical approach. Using the new observation mode “cube-mode” (where the frames were directly saved in cubes with nearly no loss of time during the readout), we obtain several thousand frames within half an hour. After the verification of the Gaussian distributed behaviour of our measurements (done with a Kolmogorov-Smirnov-Test) the measurement precision can be calculated as the standard deviation of our measurements divided by the square root of the number of frames.

To monitor the stability of the pixel scale between our observations, we use the old globular cluster 47 Tuc as a calibration system.

Keywords

astrometrymethods: statisticalinstrumentation: adaptive opticsbinaries: generalplanetary systemsglobular clusters: individual (47 Tuc)
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 3 , Symposium S248: A Giant Step: from Milli- to Micro-arcsecond Astrometry , October 2007 , pp. 48 - 51
Copyright
Copyright © International Astronomical Union 2008

References

Bean, J. L., McArthur, B. E., Benedict, G. F., Harrison, T. E. et al. 2007, ApJ, 134, 749CrossRefGoogle Scholar
Benedict, G. F., McArthur, B. E., Forveille, T., Delfosse, X. et al. 2002, ApJ, 581, 115CrossRefGoogle Scholar
Benedict, G. F., McArthur, B. E., Gatewood, G., Nelan, E. et al. 2006, ApJ, 132, 2206CrossRefGoogle Scholar
Gatewood, G. & Eichhorn, H. 1973, AJ, 78, 769CrossRefGoogle Scholar
Lippincott, S. L. 1978, Space Sci. Revs, 22, 153CrossRefGoogle Scholar
Mayor, M., Udry, S., Naef, D. et al. 2004, A&A, 74, 238Google Scholar
McArthur, B. E., Endl, M., Cochran, W. D., Benedict, G. F. et al. 2004, ApJ, 614, 81CrossRefGoogle Scholar
McLaughlin, D. E. & Anderson, J. & Meylan, G. et al. 2006, ApJS, 166, 249CrossRefGoogle Scholar
Neuhäuser, R., Guenther, E. W., Wuchterl, G. et al. 2005, A&A, 435, 13Google Scholar
Pravdo, S. H. & Shaklan, S. B. 1996, ApJ, 456, 264CrossRefGoogle Scholar
van de Kamp, P. 1969, AJ, 74, 238CrossRefGoogle Scholar