Searching for Planets Orbiting Vega with the James Webb Space Telescope

The most prominent of the IRAS debris disk systems, α Lyrae (Vega), at a distance of 7.7 pc, has been observed by both the NIRCam and MIRI instruments on the James Webb Space Telescope (JWST).

This paper describes NIRCam coronagraphic observations which have achieved F444W contrast levels of 3×10⁻⁷ at 1 arcsec (7.7 au), 1×10⁻⁷ at 2 arcsec (15 au) and few ×10⁻⁸ beyond 5 arcsec (38 au), corresponding to masses of < 3, 2 and 0.5 M_Jup for a system age of 700 Myr.

Two F444W objects are identified in the outer MIRI debris disk, around 48 au. One of these is detected by MIRI, appears to be extended and has a spectral energy distribution similar to those of distant extragalactic sources. The second one also appears extended in the NIRCam data suggestive of an extragalactic NIRCam limits within the inner disk 1 arcsec — 10 arcsec) correspond to a model-dependent masses of 2∼3m_j.

Su2024 argue that planets larger even 0.3 M_Jup would disrupt the smooth disk structure seen at MIRI wavelengths. Eight additional objects are found within 60arcsec of Vega, but none has astrometric properties or colors consistent with planet candidates. These observations reach a level consistent with expected Jeans Mass limits. Deeper observations achieving contrast levels <10⁻⁸ outside of ∼4 arcsec and reaching masses below that of Saturn are possible, but may not reveal a large population of new objects.

Charles Beichman, Geoffrey Bryden, Jorge Llop-Sayson, Marie Ygouf, Alexandra Greenbaum, Jarron Leisenring, Andras Gaspar, John Krist, George Rieke, Schuyler Wolff, Kate Su, Klaus Hodapp, Michael Meyer, Doug Kelly, Martha Boyer, Doug Johnstone, Scott Horner, Marcia Rieke

Comments: 19 pages, 12 figures. accepted for Astronomical Journal
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2410.16551 [astro-ph.EP] (or arXiv:2410.16551v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2410.16551
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Submission history
From: Chas Beichman
[v1] Mon, 21 Oct 2024 22:21:26 UTC (32,283 KB)
https://arxiv.org/abs/2410.16551

Astrobiology, Astrochemistry,