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Title: DISCOVERY OF Hα EMISSION FROM THE CLOSE COMPANION INSIDE THE GAP OF TRANSITIONAL DISK HD 142527

We utilized the new high-order 585 actuator Magellan Adaptive Optics system (MagAO) to obtain very high-resolution visible light images of HD 142527 with MagAO's VisAO science camera. In the median seeing conditions of the 6.5 m Magellan telescope (0.''5–0.''7), we find MagAO delivers 24%-19% Strehl at Hα (0.656 μm). We detect a faint companion (HD 142527B) embedded in this young transitional disk system at just 86.3 ± 1.9 mas (∼12 AU) from the star. The companion is detected in both Hα and a continuum filter (Δmag = 6.33 ± 0.20 mag at Hα and 7.50 ± 0.25 mag in the continuum filter). This provides confirmation of the tentative companion discovered by Biller and co-workers with sparse aperture masking at the 8 m Very Large Telescope. The Hα emission from the ∼0.25 solar mass companion (EW = 180 Å) implies a mass accretion rate of ∼5.9 × 10{sup –10} M {sub sun} yr{sup –1} and a total accretion luminosity of 1.2% L {sub sun}. Assuming a similar accretion rate, we estimate that a 1 Jupiter mass gas giant could have considerably better (50-1000×) planet/star contrasts at Hα than at the H band (COND models) for a range of optical extinctions (3.4-0 mag). We suggest that ∼0.5-5 M {sub jup}more » extrasolar planets in their gas accretion phase could be much more luminous at Hα than in the NIR. This is the motivation for our new MagAO GAPplanetS survey for extrasolar planets.« less
Authors:
; ; ; ; ; ; ;  [1] ; ; ;  [2] ;  [3] ;  [4]
  1. Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)
  2. INAF-Osservatorio Astrofisico di Arcetri, I-50125, Firenze (Italy)
  3. NOAO, 950 N Cherry Ave. Tucson, AZ 85719 (United States)
  4. Carnegie Institution DTM, 5241 Broad Branch Rd, Washington, DC 20015 (United States)
Publication Date:
OSTI Identifier:
22364014
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 781; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACTUATORS; APERTURES; CAMERAS; EMISSION; FILTERS; HYDROGEN; IMAGES; JUPITER PLANET; LUMINOSITY; MASS; OPTICS; RESOLUTION; STAR EVOLUTION; STARS; TELESCOPES; VISIBLE RADIATION