Izquierdo, P;
Rodríguez-Gil, P;
Gänsicke, BT;
Mustill, AJ;
Toloza, O;
Tremblay, PE;
Wyatt, M;
... Zwart, SP; + view all
(2018)
Fast spectrophotometry of WD1145+017.
Monthly Notices of the Royal Astronomical Society
, 481
(1)
pp. 703-714.
10.1093/mnras/sty2315.
Preview |
Text
sty2315.pdf - Published Version Download (1MB) | Preview |
Abstract
WD1145+017 is currently the only white dwarf known to exhibit periodic transits of planetary debris as well as absorption lines from circumstellar gas. We present the first simultaneous fast optical spectrophotometry and broad-band photometry of the system, obtained with the Gran Telescopio Canarias (GTC) and the Liverpool Telescope, respectively. The observations spanned 5.5 h, somewhat longer than the 4.5-h orbital period of the debris. Dividing the GTC spectrophotometry into five wavelength bands reveals no significant colour differences, confirming grey transits in the optical.We argue that absorption by an optically thick structure is a plausible alternative explanation for the achromatic nature of the transits that can allow the presence of small-sized (~μm) particles. The longest (87 min) and deepest (50 per cent attenuation) transit recorded in our data exhibits a complex structure around minimum light that can be well modelled by multiple overlapping dust clouds. The strongest circumstellar absorption line, Fe II λ5169, significantly weakens during this transit, with its equivalent width reducing from a mean out-of-transit value of 2 to 1Å in-transit, supporting spatial correlation between the circumstellar gas and dust. Finally, we made use of the Gaia Data Release 2 and archival photometry to determine the white dwarf parameters. Adopting a helium-dominated atmosphere containing traces of hydrogen and metals, and a reddening E(B - V) = 0.01 we find Teff= 15 020 ± 520 K, log g = 8.07 ± 0.07, corresponding to MWD= 0.63 ± 0.05M⊙and a cooling age of 224 ± 30 Myr.
| Type: | Article |
|---|---|
| Title: | Fast spectrophotometry of WD1145+017 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/sty2315 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/sty2315 |
| Language: | English |
| Additional information: | © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | minor planets, asteroids: general – planets and satellites: physical evolution – planet–star interactions – planetary systems – white dwarfs. |
| 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/10058679 |
Archive Staff Only
 |
View Item |
