August 22, 2007: CBET 1038 reports that the GCVS team has given the nova the formal name of V458 Vul. Please use 1950+20 V458 Vul for all future submissions through WebObs.
This nova has exhibited several maxima near 8th magnitude, with minima near 10th magnitude in between. The spectra likewise show large variations, with Balmer and FeII emission lines that show P Cyg profiles at the maxima that disappear during the minima. See, for example, http://www.lolife.com/astronomy/nova_vul_07 for a good blue wavelength spectra of the nova. Skoda et al. in CBET 1035 and Kiss in CBET 1038 indicate that the emission lines are broad and almost flat-topped.
Note that CCD images with 15arcmin field of view or larger will also include SS Vul, a 170-day Mira variable, towards the ENE (coordinates: 19:54:51.74 +20:55:43.3; currently at V=14.8). You might submit estimates for SS Vul at the same time as for V458 Vul, especially as the nova fades.
We are working on updating the photometry in VSP, but in the interests of providing a BVRI calibration of this field, please use the following interim values for the bright comp stars in this field (give a chart ID/date of 070822 for all submissions using these values, and list the comp stars used):
ID RA (J2000) DEC B V Rc Ic B-V
VAR 19:54:24.63 +19:54:24.6 11.12 10.34 9.01 8.74 0.78
88 19:54:07.27 +20:54:50.4 10.17 8.83 8.15 7.43 1.34
98 19:54:40.47 +20:57:01.3 11.00 9.80 9.20 8.62 1.20
100 19:55:06.27 +20:51:54.7 11.20 10.00 9.39 8.86 1.20
101 19:54:39.29 +20:45:43.2 10.26 10.15 10.10 10.01 0.11
102 19:55:07.26 +20:59:28.7 10.46 10.24 10.16 10.01 0.21
Errors on all magnitudes are 0.03mag. V and Ic magnitudes are from Richard Miles (except for 100); B and Rc magnitudes are from SRO. Note that several of these stars are red and others are blue, so at the current brightness, there is no really good color match with the variable. There are three nice 11th magnitude stars that we will use as the nova fades.
Arne Henden
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