Deep infrared imaging and spectroscopy of the nearby late M-dwarf DENIS-P J104814 –395606
✍ Scribed by R. Neuhäuser; E.W. Guenther; J. Alves; N. Grosso; Ch. Leinert; Th. Ratzka; Th. Ott; M. Mugrauer; F. Comerón; A. Eckart; W. Brandner
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 247 KB
- Volume
- 323
- Category
- Article
- ISSN
- 0004-6337
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✦ Synopsis
We obtained deep H-and K-band images of DENIS-P J104814 395606 using SofI and the speckle camera SHARP-I at the ESO-3.5m-NTT as well as QUIRC at the Mauna Kea 2.2m telescope between December 2000 and June 2001. The target was recently discovered as nearby M9-dwarf among DENIS sources . We detect parallactic motion on our images and determine the distance to be
pc, more precise than previously known. From the available colors, the distance, and the spectral type, we conclude from theoretical models that the star has a mass of ¼ ¼ to ¼ ¼ M¬ and an age of ½ to 2 Gyrs. We also obtained H-and K-band spectra of this star with ISAAC at the VLT. A faint companion candidate is detected 6 ¼ ¼ NNW of the star, which is
mag fainter in H. However, according to another image taken several month later, the companion candidate is not co-moving with the M9-dwarf. Instead, it is a non-moving background object. Limits for undetected companion candidates are such that we can exclude any stellar companions outside of ¼ ¾ ¼ ¼ (1 AU), any brown dwarf companions (above the deuterium burning mass limit) outside of ¾ ¼ ¼ (9 AU), and also any companion down to
with ¼ ½ ¼ ¼ (0.7 AU) separation, all calculated for an age of 2 Gyrs. Our observations show that direct imaging of sub-stellar companions near the deuterium burning mass limit in orbit around nearby ultra-cool dwarfs is possible, even with separations that are smaller than the semi-major axis of the outermost planet in our solar system, namely a few tens of AU.