A Search for Warm Circumstellar Disks in the 12 Myr Old Beta Pictoris Association

Biology

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

1

Scientific paper

The Beta Pictoris Association (Zuckerman et al. 2001; Song, Zuckerman & Bessell 2003) is a very close ( ˜40 pc) group of about 30 stars all of age ˜12 Myr that have common Galactic space motion indicating a common birthplace. Five of these stars, including Beta Pic itself, have infrared excesses detected by IRAS and another two have excesses detected by ISO. To search for previously undetected, tenuous, warm disks around stars in the Beta Pictoris Association, we used the Long Wavelength Spectrograph at the W. M. Keck Observatory to survey 19 stars with sensitive, 3.8, 12 and 18 \micron\ photometry.
The survey could detect Zodiacal-like dust, with temperature ˜200 K, at the level observed for Beta Pic itself. In general, disks with such a warm temperature appear to be rare. Only a handful of other disks with 12 μ m excess have been identified, including HR 7012 and HR 7329 which are also in the Beta Pic Association.
Mid-infrared observations from ground-based telescopes can be much more sensitive than IRAS (typically 40 mJy, 1σ ) at 10--20 μ m and thus detect more tenuous warm disks. Using characteristic integration times on-source of 120 and 400 s at 12 and 18 μ m, our 1σ sensitivity limits were approximately 4 mJy and 10 mJy, respectively.
At the average distance of the Beta Pic Association, IRAS had insufficient sensitivity to detect the photospheres of stars with spectral types later than A, whereas we detected photospheres down to M3. Preliminary analysis suggests that no significant infrared excesses were detected around the sample stars, although hints of excess appear in a few. It thus appears unusual for warm circumstellar dust, at temperatures characteristic of the region of the terrestrial planets, to persist around late-type stars even to 12 Myr.
We acknowledge support by the NASA Origins of Solar Systems program and the NASA Astrobiology Institute.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A Search for Warm Circumstellar Disks in the 12 Myr Old Beta Pictoris Association does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A Search for Warm Circumstellar Disks in the 12 Myr Old Beta Pictoris Association, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Search for Warm Circumstellar Disks in the 12 Myr Old Beta Pictoris Association will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1417495

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.