Nova Ophiuchi 1977
Abstract
HEAO-1 experimenters report that they have independently discovered the x-ray transient described on IAUC 3104. R. Griffiths, M. Johnston, R. Doxsey, G. Fabbiano, D. Schwartz and J. Schwarz report that the Smithsonian Astrophysical Observatory-Massachusetts Institute of Technology scanning modulation collimator, used in conjunction with the Naval Research Laboratory large-area sky survey (H. Friedman, Principal Investigator), gives two possible positions for the transient: R.A. = 17h04m02s, Decl. = -25o00' or 17h05m11s, -25o01' (equinox 1950.0; errors +/- 2s in R.A., +/- 2' in Decl.). The intensity, measured on Sept. 8 by N.R.L., was ~ 1.5 times the Crab in the energy range 0.2-1.2 keV and 1.25 times the Crab in the range 1.2-7.4 keV. A. Longmore, R. Cannon, P. Murdin and D. Malin, U.K. Schmidt Telescope Unit and Anglo-Australian Observatory, report the discovery on independent plates taken with the 122-cm Schmidt and the 380-cm telescope of a nova, its magnitude ~ 16.5 +/- 0.5 on Sept. 10, at the position R.A. = 17h05m10s.4, Decl. = -25o01'38" (equinox 1950.0), which is close to the center of the second x-ray error box. A possible precursor star is visible at the plate limit on glass copies of the red and blue Palomar Sky Survey exposures and a U.K. Schmidt IIIa-J survey plate taken on 1976 May 29. A low-dispersion spectrogram obtained by Cannon, M. Smith and A. Boksenberg with the 380-cm telescope shows a blue, featureless continuum. W. Liller, Center for Astrophysics, reports that observations with the Mt. Hopkins 150-cm telescope on Sept. 15.2, 18.1 and 19.1 UT show the star more-or-less constant at red magnitude 15.7 +/- 0.5 and approximately 0.5 magnitude bluer than the average of similar stars in the vicinity. On Sept. 18.1 the star displayed a featureless spectrum (low dispersion, range 6000-9000 A).
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- September 1977
- Bibcode:
- 1977IAUC.3110....2G