Query : 1998A&A...338..933G

1998A&A...338..933G - Astronomy and Astrophysics, volume 338, 933-946 (1998/10-3)

HST/GHRS observations of AM Herculis.


Abstract (from CDS):

We present phase-resolved spectroscopy of AM Herculis obtained with the HST/GHRS when the system was in a high state. The ultraviolet light curve shows a quasi-sinusoidal modulation, which can be explained by a hot spot on the rotating white dwarf. The broad Lyα absorption expected for photospheric radiation of a moderately hot white dwarf is largely filled in with emission. The UV/FUV spectrum of AM Her in high state can be quantitatively understood by a two-component model consisting of the unheated white dwarf plus a blackbody-like radiating hot spot. A kinematic study of the strong UV emission lines using Doppler tomography is presented. The characteristics of the low ionization species lines and the SiIV doublet can be explained within the classical picture, as broad emission from the accretion stream and narrow emission from the heated hemisphere of the secondary. However, we find that the narrow emission of the NV doublet originates from material of low velocity dispersion located somewhere between L1 and the centre of mass. The high signal-to-noise spectra contain a multitude of interstellar absorption lines but no metal absorption lines from the white dwarf photosphere.

Abstract Copyright:

Journal keyword(s): accretion, accretion disks - line: formation - stars: binaries: spectroscopic - stars: individual: AM Her - stars: white dwarfs - ultraviolet: stars

Simbad objects: 5

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Number of rows : 5
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
1 V* AM Her CV* 18 16 13.2546725112 +49 52 04.759613544   15.124 14.808 13.525   M4.5 931 0
2 V* QQ Vul CV* 20 05 41.9090048400 +22 39 58.839854760   14.688 14.656 14.584   M2 192 0
3 V* HU Aqr CV* 21 07 58.1944529400 -05 17 40.557671916   16.198 15.814 14.891   D+M4V 261 1
4 V* SS Cyg CV* 21 42 42.8034497592 +43 35 09.867842484 11.07 12.651 12.032 9.326   K5V 1251 1
5 V* IP Peg CV* 23 23 08.5362249504 +18 24 59.206884012           M2 369 0

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