McAllister, M.J., Littlefair, S.P., Baraffe, I. et al. (14 more authors) (2015) PHL 1445: An eclipsing cataclysmic variable with a substellar donor near the period minimum. Monthly Notices of the Royal Astronomical Society, 451 (1). pp. 4633-4644. ISSN 0035-8711
Abstract
We present high-speed, three-colour photometry of the eclipsing dwarf nova PHL 1445, which, with an orbital period of 76.3 min, lies just below the period minimum of ~82 min for cataclysmic variable stars. Averaging four eclipses reveals resolved eclipses of the white dwarf and bright spot. We determined the system parameters by fitting a parameterised eclipse model to the averaged lightcurve. We obtain a mass ratio of q = 0.087 +- 0.006 and inclination i = 85.2 +- 0.9 degrees. The primary and donor masses were found to be Mw = 0.73 +- 0.03 Msun and Md = 0.064 +- 0.005 Msun, respectively. Through multicolour photometry a temperature of the white dwarf of Tw = 13200 +- 700 K and a distance of 220 +- 50 pc were determined. The evolutionary state of PHL 1445 is uncertain. We are able to rule out a significantly evolved donor, but not one that is slightly evolved. Formation with a brown dwarf donor is plausible; though the brown dwarf would need to be no older than 600 Myrs at the start of mass transfer, requiring an extremely low mass ratio (q = 0.025) progenitor system. PHL 1445 joins SDSS 1433 as a sub-period minimum CV with a substellar donor. These existence of two such systems raises an alternative possibility; that current estimates for the intrinsic scatter and/or position of the period minimum may be in error.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 OUP. This is an author-produced version of a paper accepted for publication in MNRAS. Uploaded in accordance with the publisher's self-archiving policy |
Keywords: | astro-ph.SR; astro-ph.SR |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 May 2015 11:19 |
Last Modified: | 29 Jul 2015 21:47 |
Published Version: | https://dx.doi.org/10.1093/mnras/stv956 |
Status: | Published |
Publisher: | OUP |
Refereed: | Yes |
Identification Number: | 10.1093/mnras/stv956 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:85670 |