The K-band surface brightness of late-type stars and the distance to cataclysmic variables

Ramseyer, T. F.

doi:10.1086/173980

Cited by 28 publications

(36 citation statements)

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“…Bailey (1981) assumed a constant donor surface brightness in his relation, but subsequent authors have shown this quantity varies with the V − K colour (Ramseyer 1994; Beuermann 2006). Froning et al (1999) reported an updated value of 121 pc using this refinement of Ramseyer (1994) and the K ‐band measurements of Szkody & Mateo (1986). We applied the Beuermann (2006) update of Bailey's method, and found the distance to IP Peg to be 151pc.…”

Section: Discussionmentioning

confidence: 99%

Physical properties of IP Pegasi: an eclipsing dwarf nova with an unusually cool white dwarf

Copperwheat

Marsh

Dhillon

et al. 2010

Monthly Notices of the Royal Astronomical Society

132

125

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We present high‐speed photometric observations of the eclipsing dwarf nova IP Pegasi (IP Peg) taken with the triple‐beam camera ULTRACAM mounted on the William Herschel Telescope. The primary eclipse in this system was observed twice in 2004, and then a further 16 times over a 3 week period in 2005. Our observations were simultaneous in the Sloan u′, g′ and r′ bands. By phase‐folding and averaging our data, we make the first significant detection of the white dwarf ingress in this system and find the phase width φ of the white dwarf eclipse to be 0.0935 ± 0.0003, significantly higher than the previous best value of 0.0863 < φ < 0.0918. The mass ratio is found to be q=M2/M1= 0.48 ± 0.01, consistent with previous measurements, but we find the inclination to be , significantly higher than previously reported. We find the radius of the white dwarf to be 0.0063 ± 0.0003 R⊙, implying a white dwarf mass of 1.16 ± 0.02 M⊙. The donor mass is 0.55 ± 0.02 M⊙. The white dwarf temperature is more difficult to determine, since the white dwarf is seen to vary significantly in flux, even between consecutive eclipses. This is seen particularly in the u′ band, and is probably the result of absorption by disc material. Our best estimate of the temperature is 10 000–15 000 K, which is much lower than would be expected for a cataclysmic variable star with this period, and implies a mean accretion rate of <5 × 10−11 M⊙ yr−1, more than 40 times lower than the expected rate.

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Section: Discussionmentioning

confidence: 99%

Physical properties of IP Pegasi: an eclipsing dwarf nova with an unusually cool white dwarf

Copperwheat

Marsh

Dhillon

et al. 2010

Monthly Notices of the Royal Astronomical Society

132

125

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“…Figure 2 shows the surface brightness S K in the K-band vs. V-K, with V-K chosen as independent variable because it correlates well with spectral type and facilitates comparison with the results of Bailey (1981) and Ramseyer (1994). All data with V-K < 8.2 can be fitted by a third degree (n = 3) polynomial…”

Section: Spectrophotometric Stellar Samplementioning

confidence: 99%

“…Such a calibration allows to determine the radius of a star of known distance and vice versa. The dependencies on metalicity and gravity are clearly discernible in the data Table 2 is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/460/783 (Beuermann et al 1999) and were not properly taken into account in the earlier calibrations of S λ based on supergiants and applied to dwarfs (Bailey 1981;Ramseyer 1994).…”

Section: Introductionmentioning

confidence: 99%

Barnes-Evans relations for dwarfs with an application to the determination of distances to cataclysmic variables

Beuermann¹

2006

A&A

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Context. Barnes-Evans type relations provide an empirical relationship between the surface brightness of stars and their color. They are widely used for measuring the distances to stars of known radii, as the Roche-lobe filling secondaries in cataclysmic variables (CVs). Aims. The calibration of the surface brightness of field dwarfs of near-solar metalicity with spectral types A0 to L8 covers all secondary spectral types detectable in CVs and related objects and will aid in the measurement of their distances. Methods. The calibrations are based on the radii of field dwarfs measured by the Infrared Flux Method and by interferometry. Published photometry is used and homogenized to the Cousins R c and I c and the CIT JHK photometric systems. The narrow band surface brightness at 7500 Å is based on our own and published spectrophotometry. Care is taken to select the dwarfs for near-solar metalicity, appropriate to CVs, and to avoid errors caused by unrecognized binarity. Results. Relations are provided for the surface brightness in V, R c , I c , J, H, K and in a narrow band at 7500 Å as functions of V-K and of spectral type. The method is tested with selected CVs for which independent information on their distances is available. The observed spread in the radii of early M-dwarfs of given mass or luminosity and its influence on the distance measurements of CVs is discussed. Conclusions. As long as accurate trigonometric parallaxes are not routinely available for a large number of CVs, the surface brightness method remains a reliable means of determining distances to CVs in which a spectral signature of the secondary star can be discerned.

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“…This relation can be well calibrated empirically with the nearby systems, which have their distances accurately measured either with trigonometric parallaxes (Dommanget & Lampens 1992, Monet et al 1992, Gatewood 1995, or with a combination of spectroscopic and interferometric (astrometric) orbits (Pan et al 1990(Pan et al , 1992. The most accurate surface brightness determination is possible in the K-band (Ramseyer 1994).…”

Section: Detached Eclipsing Binaries As Primary Distance Indicatorsmentioning

confidence: 99%

Gravitational Microlensing, The Distance Scale, And The Ages

Paczyński

1996

Symp. - Int. Astron. Union

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Abstract. A high optical depth to gravitational microlensing towards the galactic bulge is consistent with current models of the galactic bar. The low optical depth towards the LMC can probably be accounted for by the ordinary stars in our galaxy and in the LMC itself. No conclusive evidence is available yet for the presence or absence of a large number of brown dwarfs or other non-stellar compact objects which might account for the dark matter. There is little doubt that the amount of mass in objects in the range 10~8 < M/MQ < 10 6 will be determined within the next few years with the continuing and expanding searches.Billions of photometric measurements generated by the microlensing searches have lead to the discovery of ~ 10 5 variable stars. In particular, a number of detached eclipsing binaries were discovered in the galactic bulge, in the LMC, and in the globular cluster Omega Centauri. The followup observations of these binaries will allow the determination of accurate distances to all these objects, as well as robust age determination of globular clusters.

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The K-band surface brightness of late-type stars and the distance to cataclysmic variables

Cited by 28 publications

References 0 publications

Physical properties of IP Pegasi: an eclipsing dwarf nova with an unusually cool white dwarf

Physical properties of IP Pegasi: an eclipsing dwarf nova with an unusually cool white dwarf

Barnes-Evans relations for dwarfs with an application to the determination of distances to cataclysmic variables

Gravitational Microlensing, The Distance Scale, And The Ages

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