NOVA SCORPII 2004 No 2 (V1187 Sco)
Discovered by Akira Takao, Kitakyushu, Japan
on unfiltered CCD images taken with a 120-mm telephoto lens on Aug. 3.583
UT (at V=7.8). Localization at R.A. = 17h29m18s, Decl. =-31o46'.0
(equinox 2000.0; uncertainty about 5"). See IAUC No. 8380
July. 5.918 UT 2004 Observation (estimated V
magnitude:
9.8 - see IAUC 8382)
Observatory: Castanet Tolosan (France)
- IAU959
Observer: Christian Buil
Instrument: Celestron
11 (11-inch aperture) - LHIRES2
spectrograph (sampling of 0.230 A/pixel) + Audine KAF-0401ME CCD
(bin. 2x2)
Cumulative exposure time of 45 minutes (9
x 300 seconds)
Notes: (1) The object is at very low elevation relative to
the horizon. The spectrum display a very narrow spectral interval (80 A)
at high resolution (R=14 000) - the observation is difficult for this class
of spectrograph on a 0.28 m telescope and a so fainter object.
The
setup used (click here
for details).
The spectrum acquired show only the Ha pure emission (the line cover all the field because the ejection velocity effect - FWHM measured here is near 3300 km/s - but with a large incertitude because a bad knowledge of continuum position):
The majority of narrow lines are from the atmospheric H2O. Here, a tentative for remove the earth atmosphere contribution:
The large broadening of the Ha line is very evident. The following document compare the spectrum of the nova and the spectrum of the classical Be star g Cas (v.sin i = 230 km/s). The continuum level of the nova is badly know because the small spectral coverage and the FWHM of Ha can not be precisely estimated (LHIRES2 is optimized for study small details of stars like Be, luminous supergiant, spectroscopic doubles, ... not novae !).