Farihi, J;
Becklin, EE;
Macintosh, BA;
(2004)
Mid-Infrared Observations of van Maanen 2: No Substellar Companion.
The Astrophysical Journal
, 608
(2)
L109-L112.
10.1086/422502.
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Abstract
The results of a comprehensive infrared imaging search for the putative 0.06 M☉ astrometric companion to the 4.4 pc white dwarf van Mannen 2 are reported. Adaptive optics images acquired at 3.8 μm reveal a diffraction-limited core of 0farcs09 and no direct evidence of a secondary. Models predict that at 5 Gyr, a 50MJ brown dwarf would be only 1 mag fainter than van Maanen 2 at this wavelength, and the astrometric analysis suggested a separation of 0farcs2. In the case of a chance alignment along the line of sight, a 0.4 mag excess should be measured. An independent photometric observation at the same wavelength reveals no excess. In addition, there exist published Infrared Space Observatory observations of van Maanen 2 at 6.8 and 15.0 μm that are consistent with the photospheric flux of a 6750 K white dwarf. If recent brown dwarf models are correct, there is no substellar companion with Teff gsim 500 K.
Type: | Article |
---|---|
Title: | Mid-Infrared Observations of van Maanen 2: No Substellar Companion |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1086/422502 |
Publisher version: | http://dx.doi.org/10.1086/422502 |
Language: | English |
Additional information: | Copyright © 2004. The American Astronomical Society. All rights reserved. |
Keywords: | binaries: general; stars: individual (van Maanen 2); stars: low-mass, brown dwarfs; white dwarfs |
UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
URI: | https://discovery.ucl.ac.uk/id/eprint/1477418 |
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