Searching for Gas Giant Planets on Solar System Scales: VLT NACO/APP Observations of the Debris Disk Host Stars HD172555 and HD115892
Abstract
Using the Apodizing Phase Plate (APP) coronagraph of Very Large Telescope/NACO we searched for planetary mass companions around HD115892 and HD172555 in the thermal infrared at 4 μm. Both objects harbor unusually luminous debris disks for their age and it has been suggested that small dust grains were produced recently in transient events (e.g., a collision) in these systems. Such a collision of planetesimals or protoplanets could have been dynamically triggered by yet unseen companions. We did not detect any companions in our images but derived the following detection limits: for both objects we would have detected companions with apparent magnitudes between ~13.2 and 14.1 mag at angular separations between 0farcs4 and 1farcs0 at the 5σ level. For HD115892 we were sensitive to companions with 12.1 mag even at 0farcs3. Using theoretical models these magnitudes are converted into mass limits. For HD115892 we would have detected objects with 10-15 M Jup at angular separations between 0farcs4 and 1farcs0 (7-18 AU). At 0farcs3 (~5.5 AU) the detection limit was gsim25 M Jup. For HD172555 we reached detection limits between 2 and 3 M Jup at separations between 0farcs5 and 1farcs0 (15-29 AU). At 0farcs4 (~11 AU) the detection limit was gsim4 M Jup. Despite the non-detections, our data demonstrate the unprecedented contrast performance of NACO/APP in the thermal infrared at very small inner working angles and we show that our observations are mostly background limited at separations gsim0farcs5.
Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under program number 060.A-9800(J).- Publication:
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The Astrophysical Journal
- Pub Date:
- August 2011
- DOI:
- 10.1088/2041-8205/736/2/L32
- arXiv:
- arXiv:1106.4528
- Bibcode:
- 2011ApJ...736L..32Q
- Keywords:
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- planetary systems;
- planets and satellites: detection;
- planets and satellites: formation;
- stars: formation;
- stars: individual: HD172555 HD115892;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication by ApJL