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S. Starrfield (ASU), J. Drake (CFA), R. M. Wagner (LBT), Y. Butt (CFA), P. H. Hauschildt (UGA), J. Krautter (LSW), R. D. Gehrz, C. E. Woodward (UMN), M. Della Valle (Arcetri), M. Orio (Torino), K. Mukai (GSFC), M. Hernanz (IEEC), J. W. Truran (Chicago), A. E. Evans (Keele)
V1494 Aql (Nova Aql 1999 No. 2) was discovered on 2 December 1999. It reached Vmax ~4 making it the brightest nova in the northern hemisphere since V1500 Cyg erupted in 1975. Our early optical spectra showed that it was an ``Fe II'' class nova (Williams: AJ, 104, 725, 1992). We activated our CHANDRA Target of Opportunity proposal for bright novae in outburst and obtained ACIS-I spectra on 15 April and 7 June 2000 which showed only emission lines. Our third observation on 6 August showed that it had evolved to a sharp ``emission line'' spectrum characteristic of a Super Soft X-ray Source (peak ~ 0.5 keV). We obtained HRC-S+LETG spectra on 28 Sept. (8 ksec) and 1 October (17 ksec). These spectra qualitatively resemble those of CAL 83 obtained with XMM (Paerels, F., et al. 2001, A&A, 365, L308.).
More exciting, we have analyzed the light curve of our grating observations and find that there is a factor of 6 rise in counts near the middle of the second observation which lasts about 1000 seconds and has a complex structure. Our time series analyses of these data show a 2500 sec periodicity that is not present in similar analyses of the observations of HZ 43 or Sirius B. An analysis of our HRC-S+LETG observation of V382 Vel (Nova Vel 1999) is in progress and further analyses of these data are underway.
We gratefully acknowledge partial support from NASA CHANDRA grants to CFA, OSU, UGA, and ASU.
The author(s) of this abstract have provided an email address for comments about the abstract: starrfield@asu.edu