Progress in Parallaxes at USNO

Abstract

The accuracy of trigonometric parallaxes from the U.S. Naval Observatory (USNO) has continued to improve. An optical CCD camera is used regularly on the 61-inch telescope. It produces parallaxes with typical errors of + or - 0.5 mas, and can reach + or _ 0.3 mas with some effort. The program provides distances, absolute magnitudes, and tangential velocities accurate to a few percent for many white dwarfs and low-luminosity red and brown dwarfs. Other classes of special interest being observed are planetary nebulae, cataclysmic variables, dwarf novae, and dwarf carbon stars. Some stars show residual perturbations from a close companion, and the astrometric orbital solutions indicate a brown dwarf or (in a few cases) a possible planetary-mass companion. In addition, a near-IR InSb camera is used for parallaxes of very red L and T brown dwarfs. We discuss the relationship of USNO and other programs, and the prospects for further progress.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2005
Accession Number
ADA434216

Entities

People

  • A. A. Henden
  • A. K. Monet
  • B. Canzian
  • C. B. Luginbuhl
  • C. C. Dahn
  • D. G. Monet
  • H. C. Harris
  • H. H. Guetter
  • J. A. Munn
  • S. E. Levine

Organizations

  • United States Naval Observatory

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Accuracy
  • Availability
  • Buildings And Structures
  • Celestial Brightness
  • Classification
  • Contracts
  • Demographic Cohorts
  • Errors
  • Information Operations
  • Instructions
  • Luminosity
  • Massachusetts
  • Monitoring
  • Observatories
  • Perturbations
  • Telescopes

Fields of Study

  • Physics

Readers

  • Astronomy/Astrophysics

Technology Areas

  • Space