Discovery of Water at High Spectral Resolution in the Atmosphere of 51 Peg b

By Keith Cowing
Press Release
January 25, 2017
Filed under
Discovery of Water at High Spectral Resolution in the Atmosphere of 51 Peg b

We report the detection of water absorption features in the dayside spectrum of the first-known hot Jupiter, 51 Peg b, confirming the star-planet system to be a double-lined spectroscopic binary.

We used high-resolution (R~100,000), 3.2 micron spectra taken with CRIRES/VLT to trace the radial-velocity shift of the water features in the planet’s dayside atmosphere during 4 hours of its 4.23-day orbit after superior conjunction. We detect the signature of molecular absorption by water at a significance of 5.6 sigma at a systemic velocity of Vsys=-33+/-2 km/s, coincident with the host star, with a corresponding orbital velocity Kp = 133^+4.3_-3.5 km/s. This translates directly to a planet mass of Mp=0.476^+0.032_-0.031MJ, placing it at the transition boundary between Jovian and Neptunian worlds. We determine upper and lower limits on the orbital inclination of the system of 70(Submitted on 25 Jan 2017)

Comments: 20 pages, 14 figures. Table 1 is available in full in the arXiv source file. Accepted for publication in The Astronomical Journal
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1701.07257 [astro-ph.EP] (or arXiv:1701.07257v1 [astro-ph.EP] for this version)
Submission history
From: Jayne Birkby
[v1] Wed, 25 Jan 2017 10:47:14 GMT (2213kb,D)

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