REVEALING COMPANIONS TO NEARBY STARS WITH ASTROMETRIC ACCELERATION

Journal Article · Sun Jul 15 04:00:00 EDT 2012 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/144/1/7· OSTI ID:22034401

Tokovinin, Andrei ^[1]; Hartung, Markus; Hayward, Thomas L ^[2]

---

1. Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile)
2. Gemini Observatory, Southern Operations Center, Casilla 603, La Serena (Chile)

A subset of 51 Hipparcos astrometric binaries among FG dwarfs within 67 pc has been surveyed with the Near-Infrared Coronagraphic Imager adaptive optics system at Gemini-S, directly resolving for the first time 17 subarcsecond companions and 7 wider ones. Using these data together with published speckle interferometry of 57 stars, we compare the statistics of resolved astrometric companions with those of a simulated binary population. The fraction of resolved companions is slightly lower than expected from binary statistics. About 10% of astrometric companions could be 'dark' (white dwarfs and close pairs of late M-dwarfs). To our surprise, several binaries are found with companions too wide to explain the acceleration. Re-analysis of selected intermediate astrometric data shows that some acceleration solutions in the original Hipparcos catalog are spurious.

• OSTI ID: 22034401
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 1 Vol. 144; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
ASTRONOMY
ASTROPHYSICS
BINARY STARS
CATALOGS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
INTERFEROMETRY
NEAR INFRARED RADIATION
OPTICS
STATISTICS
WHITE DWARF STARS