2002 Nov 12: Hb very strong and may be a blend with OIII.
V4742 Sgr = Nova Sgr 2002 No. 2
VSnet msg [vsnet-discovery-nova 82] There seems to be a new stellar object at (2000) R.A. 18h 02.4m, Dec. -25d 18'. It appears on three photos taken at U.T. Sept. 15.1102, 15.1227 and 15.1241 with an 80mm f/1.4 lens, orange filter and Kodak TP film; its magnitude is approximately 8.5. - William Liller.V4743 Sgr = Nova Sgr 2002 No. 3
VSnet msg [vsnet-discovery-nova 105] Katsumi Haseda (Aichi Japan) has reported possible detection of a potentially bright object (mag about 5.0) at position RA 19h 01m 08.5s Dec -22o 00' 45" (J2000.0) was recorded on a single film taken on 2002 Sep. 20.431 UT.
Even
with access to various spectrographs [SBIG
SGS, WPO
, WPO mk1, Lunar]
the Rainbow Optics
grating, like a simple screw-in filter before the CCD, will reveal the
characteristic signature of novae and broadening of the hydrogen Ha
line. As we look into the explosive shell of ejecta moving our way, the
shift is principally blue-wards.
2002 Nov 12: Hb very strong and may be a blend with OIII.
2002 Nov 3: much asprevious observation.
2002 Oct 18/21/23: Continued observation with Nova Sgr #3 imaged in late twilight low in SSW becomes routine!. IR OI emission diminished - Ha dominates.
2002 Oct 3: Best clear skies from dusk of Nova Sgr 2002#3 as it fades below mag 7 and confirms Buil's observations [VSNet] of the increased [and variable] intensity of the principle Ha emission line by a factor x6 over Hb since Sept 22/23 - now a glorious traffic-light red via the MX5c camera. Note the strong emission line in IR ~847nm and the explosive Doppler broadening of the Ha line.
2002 Sept 21 : first clear evening to record the spectra of two newly discovered nova very low down on the meridian in Sagittarius. The spectra clearly show the characteristics of novae at outburst.
2002 Sept 22/23: Follow-up observations of the starfields around the two novae and colour spectrum of Nova Sgr#3 topping the page - essentially identical to previous evening via the mono MX9 camera.
images copyright - Maurice Gavin Sept 2002
