van den Ancker, ME, Gentile Fusillo, NP, Haworth, TJ et al. (7 more authors) (2021) First detection of a disk free of volatile elements around a young A-type star: A possible sign of collisions between rocky planets. Astronomy & Astrophysics, 651 (A&A). L11. ISSN 0004-6361
Abstract
Aims. We present the first detailed analysis of the astrophysical parameters of the poorly studied Sco-Cen member HD 152384 and its circumstellar environment.
Methods. We analyse newly obtained optical-near-IR X-shooter spectra, as well as archival TESS data, of HD 152384. In addition, we use literature photometric data to construct a detailed spectral energy distribution (SED) of the star.
Results. The photospheric absorption lines in the spectrum of HD 152384 are characteristic of an A0 V star, for which we derive a stellar mass of 2.1 ± 0.1 M⊙ and a stellar age > 4.5 Myr. Superimposed on the photospheric absorption, the optical spectrum also displays double-peaked emission lines of Ca II, Fe I, Mg I, and Si I, typical of circumstellar disks. Notably, all hydrogen and helium lines appear strictly in absorption. A toy model shows that the observed emission line profiles can be reproduced by emission from a compact (radius < 0.3 au) disk seen at an inclination of ∼24°. Further evidence for the presence of circumstellar material comes from the detection of a moderate IR excess in the SED, similar to those found in extreme debris disk systems.
Conclusions. We conclude that HD 152384 is surrounded by a tenuous circumstellar disk that, although rich in refractory elements, is highly depleted of volatile elements. To the best of our knowledge, such a disk is unique among young stars. However, it is reminiscent of the disks seen in some white dwarfs, which have been attributed to the disruption of rocky planets. We suggest that the disk around HD 152384 may have a similar origin and may be due to collisions in a newly formed planetary system.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © ESO 2021. This is an author produced version of an article published in Astronomy and Astrophysics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | protoplanetary disks; circumstellar matter; stars: emission-line, Be; stars: pre-main sequence; stars: individual: HD 152384 |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Funding Information: | Funder Grant number STFC (Science and Technology Facilities Council) ST/L000628/1 STFC (Science and Technology Facilities Council) ST/P00041X/1 STFC (Science and Technology Facilities Council) Not Known |
Depositing User: | Symplectic Publications |
Date Deposited: | 11 Aug 2021 14:34 |
Last Modified: | 11 Aug 2021 14:35 |
Status: | Published |
Publisher: | EDP Sciences |
Identification Number: | 10.1051/0004-6361/202141070 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:176486 |