Precise mass and radius values for the white dwarf and low mass M dwarf in the pre‐cataclysmic binary NN Serpentis

  title={Precise mass and radius values for the white dwarf and low mass M dwarf in the pre‐cataclysmic binary NN Serpentis},
  author={Steven G. Parsons and Thomas R. Marsh and C. M. Copperwheat and Vik S. Dhillon and Stuart P. Littlefair and B. T. Gansicke and R. D. G. Hickman},
  journal={Monthly Notices of the Royal Astronomical Society},
Using the high resolution Ultraviolet and Visual Echelle Spectrograph (UVES) mounted on the Very Large Telescope in combination with photometry from the high-speed CCD camera ULTRACAM, we derive precise system parameters for the pre-cataclysmic binary NN Ser. A model fit to the ULTRACAM light curves gives the orbital inclination as i = 89 degrees.6 +/- 0 degrees.2 and the scaled radii, R-WD/a and R-sec/a. Analysis of the He (II) 4686 angstrom absorption line gives a radial velocity amplitude… 

Post Common Envelope Binaries from SDSS. XV: Accurate stellar parameters for a cool 0.4-solar mass white dwarf and a 0.16-solar mass M-dwarf in a 3 hour eclipsing binary

We identify SDSSJ121010.1+334722.9 as an eclipsing post-common-envelope binary, with an orbital period of P ~ 3 hrs, containing a very cool, low-mass, DAZ white dwarf and a low-mass main-sequence

The shortest period detached white dwarf + main-sequence binary

We present high-speed ULTRACAM and SOFI photometry and X-shooter spectroscopy of the recently discovered 94-min orbital period eclipsing white dwarf/main-sequence binary SDSS J085746.18+034255.3 (CSS

Discovery and characterization of detached M dwarf eclipsing binaries in the WFCAM Transit Survey

We report the discovery of 16 detached M-dwarf eclipsing binaries with J < 16 mag and provide a detailed characterisation of three of them, using high-precision infrared light curves from the WFCAM

The crowded magnetosphere of the post-common-envelope binary QS Virginis

We present high-speed photometry and high-resolution spectroscopy of the eclipsing post-common-envelope binary QS Virginis (QS Vir). Our Ultraviolet and Visual Echelle Spectrograph (UVES) spectra

A highly unequal-mass eclipsing M-dwarf binary in the WFCAM Transit Survey

In this paper we present the discovery of a highly unequal-mass eclipsing M-dwarf binary, providing a unique constraint on binary star formation theory and on evolutionary models for low-mass binary

A precision study of two eclipsing white dwarf plus M dwarf binaries

The mass and radius of the WD in GKVir are consistent with evolutionary models for a 50000K carbon-oxygen (CO) core WD, and the secondary star in SDSSJ1212-0123 has a radius ~9per cent larger than predicted.


Only a few well characterized very low-mass M dwarfs are known today. Our understanding of M dwarfs is vital as these are the most common stars in our solar neighborhood. We aim to characterize the

An accurate mass and radius measurement for an ultracool white dwarf

Studies of cool white dwarfs in the solar neighbourhood have placed a limit on the age of the Galactic disc of 8–9 billion years. However, determining their cooling ages requires the knowledge of

Masses and Radii of Four Very Low-mass Stars in F+M Eclipsing Binary Systems

Eclipsing binaries (EBs) with one of the companions as very low-mass stars (VLMSs; or M dwarfs) are testbeds to substantiate stellar models and evolutionary theories. Here we present four EB


We carry out high-speed photometry on 20 of the shortest-period, detached white dwarf binaries known and discover systems with eclipses, ellipsoidal variations (due to tidal deformations of the



Hubble Space Telescope Spectroscopy of V471 Tauri: Oversized K Star, Paradoxical White Dwarf

We have used the Goddard High Resolution Spectrograph on board the Hubble Space Telescope to obtain Lyα spectra of the hot white dwarf (WD) component of the short-period eclipsing DA+dK2


We present spectroscopy and photometry of GD 448, a detached white dwarf - M dwarf binary with a period of 2.47h. We find that the NaI 8200A feature is composed of narrow emission lines due to

Detection of a period decrease in NN Ser with ULTRACAM: evidence for strong magnetic braking or an unseen companion

We present results of high time resolution photometry of the eclipsing pre-cataclysmic variable NN Ser. NN Ser is a white dwarf/M dwarf binary with a very low-mass secondary star (∼0.2 M ○. ). We

HS 1857+5144: a hot and young pre-cataclysmic variable

Aims. We report the discovery of a new white dwarf/M dwarf binary, HS 1857+5144, identified in the Hamburg Quasar Survey (HQS). Methods. Time-resolved optical spectroscopy and photometry were

The Mass and Radius of the Unseen M Dwarf Companion in the Single-Lined Eclipsing Binary HAT-TR-205-013

We derive masses and radii for both components in the single-lined eclipsing binary HAT-TR-205-013, which consists of an F7 V primary and a late M dwarf secondary. The system's period is short, P =

The White Dwarf Distance to the Globular Cluster NGC 6752 (and Its Age) with the HUBBLE SPACE TELESCOPE

Deep Hubble Space Telescope (HST) observations with WFPC2 of the nearby globular cluster NGC 6752 have allowed us to obtain accurate photometry for the cluster white dwarfs (WDs). A sample of local

IUE spectra of the eclipsing binary NN Serpentis

Low-resolution SWP and LWP IUE spectra are used to fit the temperature and angular radius of the white dwarf in the detached eclipsing binary NN Ser. It is found that the redenning to the system has

Spectroscopic, orbital, and physical properties of the binary Feige 24 and detection of transient He II absorption in the system

We have obtained new high-dispersion optical spectroscopy at Kitt Peak National Observatory (KPNO) and new International Ultraviolet Explorer (IUE) spectroscopy of the white dwarf+red dwarf binary

High-resolution optical spectroscopy of Praesepe white dwarfs

We present the results of a high-resolution optical spectroscopic study of nine white dwarf candidate members of Praesepe undertaken with the VLT and Ultraviolet and Visual Echelle Spectrograph. We

On the evolutionary status of short-period cataclysmic variables

We present high-speed, three-colour photometry of seven short-period (P-orb <= 95 min) eclipsing cataclysmic variables (CVs) from the Sloan Digital Sky Survey. We determine the system parameters via