Dr Steven Parsons

Department of Physics and Astronomy

STFC Ernest Rutherford Fellow

Dr Steven Parsons
Profile picture of Dr Steven Parsons
s.g.parsons@sheffield.ac.uk
+44 114 222 3558

Full contact details

Dr Steven Parsons
Department of Physics and Astronomy
F37
Hicks Building
Hounsfield Road
Sheffield
S3 7RH
Profile

I am an Ernest Rutherford Fellow in the astronomy group at the University of Sheffield. I earned my MPhys in Physics with Astrophysics at the University of Kent in 2008, followed by a PhD at the University of Warwick under the supervision of Professor Tom Marsh.

After receiving my PhD in 2012 I moved to the Universidad de Valparaiso in Chile as an ESO/Comite Mixto Post Doctoral research associate. One year into this postion I was awarded a 3 year FONDECYT Post Doctoral fellowship at Valparaiso, which I finished in 2016.

I moved to Sheffield in July 2016 as part of a 1 year Post Doc with Prof. Vik Dhillon working on the HiPERCAM project, before starting a Leverhulme Early Career Fellowship in 2017. Two years into my Leverhulme Fellowship I was awarded a STFC Ernest Rutherford Fellowship.

Research interests

My research involves the study of white dwarfs, the incredibly dense burnt out embers of former stars. White dwarfs have masses similar to the Sun, but are only the size of the Earth.

Many are found in binary systems with other stars or white dwarfs, a few of which are aligned with the Earth such that one star passes in front of the other, causing regular eclipses.

I use a range of telescopes from around the world to search for and study these eclipsing binaries in order to better understand the structure and composition of white dwarfs as well as the evolution and fate of these binaries.

There is a theoretical upper limit to the mass of a white dwarf, known as the Chandrasekhar mass. If a white dwarf gains mass (e.g. from a binary companion) and reaches this limit it will blow up in an explosion known as a Type Ia supernova, visible from across the Universe.

These supernovae are extremely useful to cosmologists since their distances can be reliably measured, leading to the discovery of the accelerating expansion of the Universe and the existence of dark energy.

However, how the white dwarf gains the mass, and the nature of its binary companion are not well known.

I search for the progenitors of type Ia supernovae in our own Galaxy to better understand how they are created and whether or not the existence of multiple formation channels could ultimately limit their use as distance indicators.

Publications

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Journal articles

All publications

Journal articles

Conference proceedings papers

  • Bezawada N, Gao X, Henry D, Black M, Miller C, Lunney D, Dhillon V, Littlefair S, Kerry P, Gamble T , Dixon S et al (2018) Configuration of readout electronics and data acquisition for the HiPERCAM instrument. Proceedings of SPIE, Vol. 10709, 10 June 2018 - 15 June 2018. View this article in WRRO RIS download Bibtex download
  • Dhillon V, Dixon S, Gamble T, Kerry P, Littlefair S, Parsons S, Marsh T, Bezawada N, Black M, Gao X , Henry D et al (2018) First light with HiPERCAM on the GTC. Proceedings of SPIE, Vol. 10702, 10 June 2018 - 15 June 2018. View this article in WRRO RIS download Bibtex download
  • Wilson DJ, Gaensicke BT, Koester D, Raddi R, Breedt E, Southworth J & Parsons SG (2015) Variable Emission from a Gaseous Disc around a Metal-Polluted White Dwarf. 19TH EUROPEAN WORKSHOP ON WHITE DWARFS, Vol. 493 (pp 279-284) RIS download Bibtex download
  • Bours MCP, Marsh TR, Parsons SG, Copperwheat CM, Dhillon VS, Littlefair SP, Gaensicke BT, Gianninas A & Tremblay P-E (2015) A Detailed Study of CSS 41177: an Eclipsing Double White Dwarf. 19TH EUROPEAN WORKSHOP ON WHITE DWARFS, Vol. 493 (pp 313-318) RIS download Bibtex download
  • Bours MCP, Marsh TR & Parsons SG (2013) Planets Around White Dwarf Binaries. 18TH EUROPEAN WHITE DWARF WORKSHOP, Vol. 469 (pp 451-+) RIS download Bibtex download
  • Hessman FV, Beuermann K, Dreizler S, Marsh TR, Parsons SG, Copperwheat CM, Winget DE, Miller GF, Hermes JJ, Schreiber MR , Kley W et al (2011) The Planets around the post-Common Envelope Binary NN Serpentis. PLANETARY SYSTEMS BEYOND THE MAIN SEQUENCE: Proceedings of the International Conference RIS download Bibtex download
  • Dreizler S, Beuermann K, Hessman FV, Marsh TR, Parsons SG, Dhillon VS, Schreiber MR, Kley W, Miller GF, Werner K & Rauch T (2010) Evidence for planets orbiting the post-common envelope binary NN Serpentis. 17TH EUROPEAN WHITE DWARF WORKSHOP RIS download Bibtex download

Preprints

  • Pelisoli I, Chomiuk L, Strader J, Marsh TR, Aydi E, Dage KC, Kyer R, Molina I, Panurach T, Urquhart R , Maccarone TJ et al (2024) A Survey for Radio Emission from White Dwarfs in the VLA Sky Survey, arXiv. RIS download Bibtex download
  • Hollands MA, Littlefair SP & Parsons SG (2023) Measuring the Initial-Final Mass-Relation using wide double white dwarf binaries from Gaia DR3, arXiv. RIS download Bibtex download
  • Littlefair SP, Rodríguez-Gil P, Marsh TR, Parsons SG & Dhillon VS (2023) The donor star radial velocity curve in the cataclysmic variable GY Cnc confirms white dwarf eclipse modelling mass, arXiv. RIS download Bibtex download
  • Green MJ, Hermes JJ, Barlow BN, Marsh TR, Pelisoli I, Gänsicke BT, Kaiser BC, Romero A, Amaral LA, Corcoran K , Grupe D et al (2023) TIC 378898110: A Bright, Short-Period AM CVn Binary in TESS. RIS download Bibtex download
  • Caiazzo I, Burdge KB, Tremblay P-E, Fuller J, Ferrario L, Gaensicke BT, Hermes JJ, Heyl J, Kawka A, Kulkarni SR , Marsh TR et al (2023) A rotating white dwarf shows different compositions on its opposite faces, arXiv. RIS download Bibtex download
  • Munday J, Tremblay P-E, Hermes JJ, Barlow B, Pelisoli I, Marsh TR, Parsons SG, Jones D, Kepler SO, Brown A , Littlefair SP et al (2023) An Eclipsing 47 minute Double White Dwarf Binary at 400 pc. RIS download Bibtex download
  • Levan A, Gompertz B, Salafia OS, Bulla M, Burns E, Hotokezaka K, Izzo L, Lamb G, Malesani D, Oates S , Ravasio M et al (2023) JWST detection of heavy neutron capture elements in a compact object merger, Research Square Platform LLC. RIS download Bibtex download
  • Farihi J, Hermes JJ, Littlefair SP, Howarth ID, Walters N & Parsons SG (2023) Discovery of Dipolar Chromospheres in Two White Dwarfs. RIS download Bibtex download
  • Levan A, Gompertz BP, Salafia OS, Bulla M, Burns E, Hotokezaka K, Izzo L, Lamb GP, Malesani DB, Oates SR , Ravasio ME et al (2023) JWST detection of heavy neutron capture elements in a compact object merger. RIS download Bibtex download
  • Pelisoli I, Marsh TR, Buckley DAH, Heywood I, Potter SB, Schwope A, Brink J, Standke A, Woudt PA, Parsons SG , Green MJ et al (2023) A 5.3-minute-period pulsing white dwarf in a binary detected from radio to X-rays. RIS download Bibtex download
  • Brown AJ, Parsons SG, van Roestel J, Rebassa-Mansergas A, Breedt E, Dhillon VS, Dyer MJ, Green MJ, Kerry P, Littlefair SP , Marsh TR et al (2023) Photometric follow-up of 43 new eclipsing white dwarf plus main-sequence binaries from the ZTF survey, arXiv. RIS download Bibtex download
  • Munday J, Marsh TR, Hollands M, Pelisoli I, Steeghs D, Hakala P, Breedt E, Brown A, Dhillon VS, Dyer MJ , Green M et al (2022) Two decades of optical timing of the shortest-period binary star system HM Cancri, arXiv. RIS download Bibtex download
  • Caiazzo I, Burdge K, Ferrario L, Fuller J, Gänsicke B, Hermes JJ, Heyl J, Kawka A, Kulkarni S, Marsh T , Mroz P et al (2022) A rotating white dwarf with two faces, Research Square Platform LLC. RIS download Bibtex download
  • Dhillon VS, Kennedy MR, Breton RP, Clark CJ, Sánchez DM, Voisin G, Breedt E, Brown AJ, Dyer MJ, Green MJ , Kerry P et al (2022) Multi-colour optical light curves of the companion star to the millisecond pulsar PSR J2051-0827, arXiv. View this article in WRRO RIS download Bibtex download
  • Pelisoli I, Marsh TR, Parsons SG, Aungwerojwit A, Ashley RP, Breedt E, Brown AJ, Dhillon VS, Dyer MJ, Green MJ , Kerry P et al (2022) Long-term photometric monitoring and spectroscopy of the white dwarf pulsar AR Scorpii, arXiv. RIS download Bibtex download
  • Brown AJ, Parsons SG, Littlefair SP, Wild JF, Ashley RP, Breedt E, Dhillon VS, Dyer MJ, Green MJ, Kerry P , Marsh TR et al (2022) Characterising eclipsing white dwarf M dwarf binaries from multi-band eclipse photometry, arXiv. RIS download Bibtex download
  • Jones D, Munday J, Corradi R, Rodríguez-Gil P, Boffin H, Zak J, Sowicka P, Parsons S, Dhillon V, Littlefair S , Marsh T et al (2021) The post-common-envelope binary central star of the planetary nebula Ou 5: a doubly-eclipsing post-red-giant-branch system, arXiv. RIS download Bibtex download
  • Stevance HF, Parsons SG & Eldridge JJ (2021) To be or not to be a black hole: detailed binary population models as a sanity check. RIS download Bibtex download
  • Pelisoli I, Marsh TR, Ashley RP, Hakala P, Aungwerojwit A, Burdge K, Breedt E, Brown AJ, Chanthorn K, Dhillon VS , Dyer MJ et al (2021) Optical detection of the rapidly spinning white dwarf in V1460 Her, arXiv. RIS download Bibtex download
  • Pelisoli I, Marsh TR, Dhillon VS, Breedt E, Brown AJ, Dyer MJ, Green MJ, Kerry P, Littlefair SP, Parsons SG , Sahman DI et al (2021) Found: a rapidly spinning white dwarf in LAMOST J024048.51+195226.9, arXiv. RIS download Bibtex download
  • Dhillon VS, Bezawada N, Black M, Dixon SD, Gamble T, Gao X, Henry DM, Kerry P, Littlefair SP, Lunney DW , Marsh TR et al (2021) HiPERCAM: a quintuple-beam, high-speed optical imager on the 10.4-m Gran Telescopio Canarias, arXiv. RIS download Bibtex download
  • Wild JF, Littlefair SP, Ashley RP, Breedt E, Brown A, Dhillon VS, Dyer MJ, Green MJ, Kerry P, Marsh TR , Parsons SG et al (2021) System parameters of three short period cataclysmic variable stars, arXiv. RIS download Bibtex download
  • Parsons SG, Gänsicke BT, Schreiber MR, Marsh TR, Ashley RP, Breedt E, Littlefair SP & Meusinger H (2021) Magnetic white dwarfs in post-common-envelope binaries, arXiv. RIS download Bibtex download
  • Casewell SL, Belardi C, Parsons SG, Littlefair SP, Braker IP, Hermes JJ, Debes J, Vanderbosch Z, Burleigh MR, Gaensicke BT , Dhillon VS et al (2020) WD1032+011, an inflated brown dwarf in an old eclipsing binary with a white dwarf, arXiv. RIS download Bibtex download
  • Green MJ, Marsh TR, Carter PJ, Steeghs D, Breedt E, Dhillon VS, Littlefair SP, Parsons SG, Kerry P, Fusillo NPG , Ashley RP et al (2020) Spectroscopic and Photometric Periods of Six Ultracompact Accreting Binaries, arXiv. RIS download Bibtex download
  • Parsons SG, Brown AJ, Littlefair SP, Dhillon VS, Marsh TR, Hermes JJ, Istrate AG, Breedt E, Dyer MJ, Green MJ & Sahman DI (2020) A pulsating white dwarf in an eclipsing binary, arXiv. RIS download Bibtex download
  • McAllister M, Littlefair SP, Parsons SG, Dhillon VS, Marsh TR, Gaensicke BT, Breedt E, Copperwheat C, Green MJ, Knigge C , Sahman DI et al (2019) The evolutionary status of Cataclysmic Variables: Eclipse modelling of 15 systems, arXiv. RIS download Bibtex download
  • Rebassa-Mansergas A, Parsons SG, Dhillon VS, Ren J, Littlefair SP, Marsh TR & Torres S (2019) Accurate mass and radius determinations of a cool subdwarf in an eclipsing binary, arXiv. RIS download Bibtex download
  • Casewell SL, Littlefair SP, Parsons SG, Marsh TR, Fortney JJ & Marley MS (2018) The direct detection of the irradiated brown dwarf in the white dwarf - brown dwarf binary SDSS J141126.20+200911.1, arXiv. RIS download Bibtex download
  • Parsons SG, Gänsicke BT, Marsh TR, Ashley RP, Breedt E, Burleigh MR, Copperwheat CM, Dhillon VS, Green MJ, Hermes JJ , Irawati P et al (2018) The scatter of the M dwarf mass-radius relationship, arXiv. RIS download Bibtex download
  • Dhillon V, Dixon S, Gamble T, Kerry P, Littlefair S, Parsons S, Marsh T, Bezawada N, Black M, Gao X , Henry D et al (2018) First light with HiPERCAM on the GTC, arXiv. RIS download Bibtex download
  • Green MJ, Hermes JJ, Marsh TR, Steeghs DTH, Bell KJ, Littlefair SP, Parsons SG, Dennihy E, Fuchs JT, Reding JS , Kaiser BC et al (2018) A 15.7-Minute AM CVn Binary Discovered in K2, arXiv. RIS download Bibtex download
  • Green MJ, Marsh TR, Steeghs DTH, Kupfer T, Ashley RP, Bloemen S, Breedt E, Campbell HC, Chakpor A, Copperwheat CM , Dhillon VS et al (2018) High-Speed Photometry of Gaia14aae: An Eclipsing AM CVn That Challenges Formation Models, arXiv. RIS download Bibtex download
  • Casewell SL, Braker IP, Parsons SG, Hermes JJ, Burleigh MR, Belardi C, Chaushev A, Finch NL, Roy M, Littlefair SP , Goad M et al (2018) The first sub-70 minute non-interacting WD-BD system: EPIC212235321, arXiv. RIS download Bibtex download
  • Hardy LK, Dhillon VS, Spitler LG, Littlefair SP, Ashley RP, De Cia A, Green MJ, Jaroenjittichai P, Keane EF, Kerry P , Kramer M et al (2017) A search for optical bursts from the repeating fast radio burst FRB 121102, arXiv. RIS download Bibtex download
  • Parsons SG, Gänsicke BT, Marsh TR, Ashley RP, Bours MCP, Breedt E, Burleigh MR, Copperwheat CM, Dhillon VS, Green M , Hardy LK et al (2017) Testing the white dwarf mass-radius relationship with eclipsing binaries, arXiv. RIS download Bibtex download
  • Parsons SG, Hermes JJ, Marsh TR, Gänsicke BT, Tremblay P-E, Littlefair SP, Sahman DI, Ashley RP, Green M, Rattanasoon S , Dhillon VS et al (2017) Two white dwarfs in ultrashort binaries with detached, eclipsing, likely substellar companions detected by K2, arXiv. RIS download Bibtex download
  • Hallakoun N, Xu S, Maoz D, Marsh TR, Ivanov VD, Dhillon VS, Bours MCP, Parsons SG, Kerry P, Sharma S , Su K et al (2017) Once in a blue moon: detection of 'bluing' during debris transits in the white dwarf WD1145+017, arXiv. RIS download Bibtex download
  • Breedt E, Steeghs D, Marsh TR, Fusillo NPG, Tremblay P-E, Green M, De Pasquale S, Hermes JJ, Gänsicke BT, Parsons SG , Bours MCP et al (2017) Using large spectroscopic surveys to test the double degenerate model for Type Ia supernovae, arXiv. RIS download Bibtex download
  • McAllister MJ, Littlefair SP, Dhillon VS, Marsh TR, Gänsicke BT, Bochinksi J, Bours MCP, Breedt E, Hardy LK, Hermes JJ , Kengkriangkrai S et al (2017) SDSS J105754.25+275947.5: a period-bounce eclipsing cataclysmic variable with the lowest-mass donor yet measured, arXiv. RIS download Bibtex download
  • Hardy LK, McAllister MJ, Dhillon VS, Littlefair SP, Bours MCP, Breedt E, Butterley T, Chakpor A, Irawati P, Kerry P , Marsh TR et al (2016) Hunting For Eclipses: High Speed Observations of Cataclysmic Variables, arXiv. RIS download Bibtex download
  • Marsh TR, Gänsicke BT, Hümmerich S, Hambsch F-J, Bernhard K, Lloyd C, Breedt E, Stanway ER, Steeghs DT, Parsons SG , Toloza O et al (2016) A radio pulsing white dwarf binary star, arXiv. RIS download Bibtex download
  • Bours MCP, Marsh TR, Parsons SG, Dhillon VS, Ashley RP, Bento JP, Breedt E, Butterley T, Caceres C, Copperwheat CM , Hardy LK et al (2016) Long-term eclipse timing of white dwarf binaries: an observational hint of a magnetic mechanism at work, arXiv. RIS download Bibtex download
  • Parsons SG, Hill CA, Marsh TR, Gansicke BT, Watson CA, Steeghs D, Dhillon VS, Littlefair SP, Copperwheat CM, Schreiber MR & Zorotovic M (2016) The crowded magnetosphere of the post common envelope binary QS Virginis, arXiv. RIS download Bibtex download
  • Irawati P, Richichi A, Bours MCP, Marsh TR, Sanguansak N, Chanthorn K, Hermes JJ, Hardy LK, Parsons SG, Dhillon VS & Littlefair SP (2015) A large, long-lived structure near the trojan L5 point in the post common-envelope binary SDSS J1021+1744, arXiv. RIS download Bibtex download
  • McAllister MJ, Littlefair SP, Baraffe I, Dhillon VS, Marsh TR, Bento J, Bochinski J, Bours MCP, Breedt E, Copperwheat CM , Hardy LK et al (2015) PHL 1445: An eclipsing cataclysmic variable with a substellar donor near the period minimum, arXiv. RIS download Bibtex download
  • Parsons SG, Agurto-Gangas C, Gaensicke BT, Rebassa-Mansergas A, Schreiber MR, Marsh TR, Dhillon VS, Littlefair SP, Drake AJ, Bours MCP , Breedt E et al (2015) Fourteen new eclipsing white dwarf plus main-sequence binaries from the SDSS and Catalina surveys, arXiv. RIS download Bibtex download
  • Pyrzas S, Gaensicke BT, Hermes JJ, Copperwheat CM, Rebassa-Mansergas A, Dhillon VS, Littlefair SP, Marsh TR, Parsons SG, Savoury CDJ , Schreiber MR et al (2014) Discovery of ZZ Cetis in detached white dwarf plus main-sequence binaries, arXiv. RIS download Bibtex download
  • Bours M, Marsh T, Breedt E, Copperwheat C, Dhillon V, Leckngam A, Littlefair S, Parsons S & Prasit A (2014) Testing the planetary models of HU Aquarii, arXiv. RIS download Bibtex download
  • Littlefair SP, Casewell SL, Parsons SG, Dhillon VS, Marsh TR, Gaensicke BTG, Bloemen S, Catalan S, Irawati P, Hardy LK , Mcallister M et al (2014) The substellar companion in the eclipsing white dwarf binary SDSS J141126.20+200911.1, arXiv. RIS download Bibtex download
  • Bours MCP, Marsh TR, Parsons SG, Copperwheat CM, Dhillon VS, Littlefair SP, Gänsicke BT, Gianninas A & Tremblay P-E (2014) Precise parameters for both white dwarfs in the eclipsing binary CSS 41177, arXiv. RIS download Bibtex download
  • Parsons SG, Marsh TR, Bours MCP, Littlefair SP, Copperwheat CM, Dhillon VS, Breedt E, Caceres C & Schreiber MR (2013) Timing variations in the secondary eclipse of NN Ser, arXiv. RIS download Bibtex download
  • Bento J, Wheatley PJ, Copperwheat CM, Fortney JJ, Dhillon VS, Hickman R, Littlefair SP, Marsh TR, Parsons SG & Southworth J (2013) Optical transmission photometry of the highly inflated exoplanet WASP-17b, arXiv. RIS download Bibtex download
  • Marsh TR, Parsons SG, Bours MCP, Littlefair SP, Copperwheat CM, Dhillon VS, Breedt E, Caceres C & Schreiber MR (2013) The planets around NN Ser: still there, arXiv. RIS download Bibtex download
  • Parsons SG, Marsh TR, Gänsicke BT, Schreiber MR, Bours MCP, Dhillon VS & Littlefair SP (2013) A magnetic white dwarf in a detached eclipsing binary, arXiv. RIS download Bibtex download
  • Steeghs D, McClintock JE, Parsons SG, Reid MJ, Littlefair S & Dhillon VS (2013) The not-so-massive black hole in the microquasar GRS1915+105, arXiv. RIS download Bibtex download
  • Parsons SG, Gänsicke BT, Marsh TR, Drake AJ, Dhillon VS, Littlefair SP, Pyrzas S, Rebassa-Mansergas A & Schreiber MR (2012) Eclipsing Post Common Envelope Binaries from the Catalina Surveys, arXiv. RIS download Bibtex download
  • Parsons SG, Gänsicke BT, Marsh TR, Bergeron P, Copperwheat CM, Dhillon VS, Bento J, Littlefair SP & Schreiber MR (2012) An accurate mass and radius measurement for an ultracool white dwarf, arXiv. RIS download Bibtex download
  • Savoury CDJ, Littlefair SP, Marsh TR, Dhillon VS, Parsons SG, Copperwheat CM & Steeghs D (2012) A Radial Velocity Study of CTCV J1300-3052, arXiv. RIS download Bibtex download
  • Copperwheat CM, Marsh TR, Parsons SG, Hickman R, Steeghs D, Breedt E, Dhillon VS, Littlefair SP & Savoury C (2011) A J-band detection of the donor star in the dwarf nova OY Carinae, and an optical detection of its `iron curtain', arXiv. RIS download Bibtex download
  • Parsons SG, Marsh TR, Gänsicke BT, Rebassa-Mansergas A, Dhillon VS, Littlefair SP, Copperwheat CM, Hickman RDG, Burleigh MR, Kerry P , Koester D et al (2011) A precision study of two eclipsing white dwarf plus M dwarf binaries, arXiv. RIS download Bibtex download
  • Parsons SG, Marsh TR, Gänsicke BT, Dhillon VS, Copperwheat CM, Littlefair SP, Pyrzas S, Drake AJ, Koester D, Schreiber MR & Rebassa-Mansergas A (2011) The shortest period detached white dwarf + main-sequence binary, arXiv. RIS download Bibtex download
  • Savoury CDJ, Littlefair SP, Dhillon VS, Marsh TR, Gaensicke BT, Copperwheat CM, Kerry P, Hickman RDG & Parsons SG (2011) Cataclysmic Variables below the Period Gap: Mass Determinations of 14 Eclipsing Systems, arXiv. RIS download Bibtex download
  • Hessman FV, Beuermann K, Dreizler S, Marsh TR, Parsons SG, Copperwheat CM, Winget DE, Miller GF, Hermes JJ, Schreiber MR , Kley W et al (2011) The Planets around the Post-Common Envelope Binary NN Serpentis, arXiv. RIS download Bibtex download
  • Beuermann K, Hessman FV, Dreizler S, Marsh TR, Parsons SG, Winget DE, Miller GF, Schreiber MR, Kley W, Dhillon VS , Littlefair SP et al (2010) Two planets orbiting the recently formed post-common envelope binary NN Serpentis, arXiv. RIS download Bibtex download
  • Parsons SG, Marsh TR, Copperwheat CM, Dhillon VS, Littlefair SP, Hickman RDG, Maxted PFL, Gänsicke BT, Unda-Sanzana E, Colque JP , Barraza N et al (2010) Orbital Period Variations in Eclipsing Post Common Envelope Binaries, arXiv. RIS download Bibtex download
  • Parsons SG, Marsh TR, Copperwheat CM, Dhillon VS, Littlefair SP, Gansicke BT & Hickman R (2009) Precise mass and radius values for the white dwarf and low mass M dwarf in the pre-cataclysmic binary NN Serpentis, arXiv. RIS download Bibtex download