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Title: CONSTRAINING THE ANGULAR MOMENTUM EVOLUTION OF V455 ANDROMEDAE

Time-series photometry on the cataclysmic variable V455 Andromedae (hereafter V455 And, HS 2331+3905) reveals a rotation period shorter than the orbital period, implying the presence of a magnetic field. We expect that this magnetic field channels the accreted matter from the disk toward the white dwarf poles, classifying it as an Intermediate Polar. The two polar spinning emission areas are visible in the lightcurves at the rotation period of 67.61970396 ± 0.00000072 s, and its harmonic. Using photometric observations of V455 And obtained from 2007 October to 2015, we derive 3σ upper limits to the rate of change of the spin harmonic (SH) with time to be dP{sub SH}/dt ≤ −7.5 × 10{sup −15} s s{sup −1} employing the O–C method, and −5.4 × 10{sup −15} s s{sup −1} with a direct nonlinear least squares fit. There is no significant detection of a changing spin period for the duration of 2007 October–2015. The 3σ upper limit for the rate of change of spin period with time is dP{sub spin}/dt ≤ −10.8 × 10{sup −15} s s{sup −1} or −0.34 μs yr{sup −1}. V455 And underwent a large-amplitude dwarf nova outburst in 2007 September. The pre-outburst data reflect a period 4.8 ± 2.2 μs longermore » than the best-fit post-outburst spin period. The angular momentum gained by the white dwarf from matter accreted during outburst and its slight subsequent shrinking should both cause the star to spin slightly faster after the outburst. We estimate that the change in spin period due to the outburst should be 5 μs, consistent with the empirical determination of 4.8 ± 2.2 μs (3σ upper limit of 11.4 μs)« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ; ; ; ; ;  [7] ;  [8]
  1. Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States)
  2. Qatar Environment and Energy Research Institute (QEERI), HBKU, Qatar Foundation, P.O. Box 5825, Doha (Qatar)
  3. Department of Physics and Astronomy, The University of Alabama, Tuscaloosa, AL 35487 (United States)
  4. Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom)
  5. Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255 (United States)
  6. Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)
  7. Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)
  8. CBA-Wilts, 2 Spa Close, Highworth, Swindon, Wilts SN6 7PJ (United Kingdom)
Publication Date:
OSTI Identifier:
22518515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 821; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; GAIN; LEAST SQUARE FIT; MAGNETIC FIELDS; NONLINEAR PROBLEMS; NOVAE; PHOTOMETRY; ROTATION; SPIN; VARIABLE STARS; WHITE DWARF STARS