Mehner, A;
de Wit, W-J;
Asmus, D;
Morris, PW;
Agliozzo, C;
Barlow, MJ;
Gull, TR;
... Weigelt, G; + view all
(2019)
Mid-infrared evolution of eta Carinae from 1968 to 2018.
Astronomy & Astrophysics
, 630
, Article L6. 10.1051/0004-6361/201936277.
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Abstract
η Car is one of the most luminous and massive stars in our Galaxy and is the brightest mid-IR source in the sky outside our solar system. Since the late 1990s, the central source has dramatically brightened at UV and optical wavelengths. This might be explained by a decrease in circumstellar dust extinction. We aim to establish the mid-IR flux evolution and further our understanding of the star’s UV and optical brightening. Mid-IR images from 8−20 µm were obtained in 2018 with VISIR at the Very Large Telescope. Archival data from 2003 and 2005 were retrieved from the ESO Science Archive Facility, and historical records were collected from publications. We present mid-IR images of η Car with the highest angular resolution to date at the corresponding wavelengths (≥0.2200). We reconstruct the mid-IR evolution of the spectral energy distribution of the spatially integrated Homunculus nebula from 1968 to 2018 and find no long-term changes. The bolometric luminosity of η Car has been stable over the past five decades. We do not observe a long-term decrease in the mid-IR flux densities that could be associated with the brightening at UV and optical wavelengths, but circumstellar dust must be declining in our line of sight alone. Short-term flux variations within about 25% of the mean levels could be present.
| Type: | Article |
|---|---|
| Title: | Mid-infrared evolution of eta Carinae from 1968 to 2018 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1051/0004-6361/201936277 |
| Publisher version: | https://doi.org/10.1051/0004-6361/201936277 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | circumstellar matter – stars: individual: η Car – stars: massive – stars: mass-loss – stars: variables: S Doradus – stars: winds, outflows |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10084726 |
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