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

Journal Article · Sat Feb 01 04:00:00 EST 2014 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/781/2/L30· OSTI ID:22364014

Close, L. M.; Follette, K. B.; Males, J. R.; Apai, D.; Morzinski, K.; Rodigas, T. J.; Hinz, P.; Bailey, V. ^[1]; Puglisi, A.; Xompero, M.; Briguglio, R. ^[2]; Najita, J. ^[3]

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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)

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} 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.

• OSTI ID: 22364014
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 781; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACTUATORS
APERTURES
CAMERAS
EMISSION
FILTERS
HYDROGEN
IMAGES
JUPITER PLANET
LUMINOSITY
MASS
OPTICS
RESOLUTION
STAR EVOLUTION
STARS
TELESCOPES
VISIBLE RADIATION