(vsnet-discovery-nova 26, vsnet-alert 7088)
Katsumi Haseda (Aichi, Japan) reports the discovery of a possible nova in Oph (HadV105).
Haseda provides the following semi-accurate coordinates (possible uncertainty 10"):
17h 37m 34.5s, -16o 23' 22" (J2000.0)
There is no known or suspected variable, no bright (brighter than 14.5) DSS star and no bright 2MASS source at the reported position. No known (bright) minor planet is found at this position.
The object is thus very likely a nova or a some sort of exploding object. Confirmatory observations, accurate astrometry, photometry and spectroscopy are most urgently requested.
Finding charts are placed at:
Photographic magnitude estimates by VSOLJ members
object YYYYMMDD(UT) mag code HadV105 19970823.500 <131p Had.VSOLJ HadV105 19980330.774 <131p Had.VSOLJ HadV105 19990115.852 <131p Had.VSOLJ HadV105 19990216.830 <131p Had.VSOLJ HadV105 19990323.776 <131p Had.VSOLJ HadV105 19990803.539 <125p Had.VSOLJ HadV105 19990830.471 <131p Had.VSOLJ HadV105 20000206.829 <131p Had.VSOLJ HadV105 20000429.724 <131p Had.VSOLJ HadV105 20000604.599 <125p Had.VSOLJ HadV105 20000708.590 <125p Had.VSOLJ HadV105 20000802.508 <131p Had.VSOLJ HadV105 20000822.495 <131p Had.VSOLJ HadV105 20000824.477 <125p Had.VSOLJ HadV105 20010202.856 <131p Had.VSOLJ HadV105 20010226.807 <131p Had.VSOLJ HadV105 20010304.806 <131p Had.VSOLJ HadV105 20010319.782 <131p Had.VSOLJ HadV105 20010326.782 <131p Had.VSOLJ HadV105 20010331.790 <131p Had.VSOLJ HadV105 20010422.759 <131p Had.VSOLJ HadV105 20010512.581 <131p Had.VSOLJ HadV105 20010517.639 <131p Had.VSOLJ HadV105 20010528.620 <131p Had.VSOLJ HadV105 20010615.672 <131p Had.VSOLJ HadV105 20010626.619 <125p Had.VSOLJ HadV105 20010713.572 <131p Had.VSOLJ HadV105 20010724.556 <125p Had.VSOLJ HadV105 20010911.509 <131p Had.VSOLJ HadV105 20010916.492 <125p Had.VSOLJ HadV105 20011011.426 <131p Had.VSOLJ HadV105 20020124.838 90p Had.VSOLJ Observer's code: Had: K. Haseda (Aichi, Japan) Instruments: 10cm F4.0 twin patrol camera +T-Max400(120)
A new object is present at 17h 37m 34.60s -16o 23' 23.2" (+/- 0.6") with magnitude V = 9.22 +/- 0.08. at 1/26/02 12:39 UT. The position is based on CCD astrometry using 8 GSC stars. The comparison stars for photometry were TYC 6248 1077 1 and TYC 6248 794 1. The check star was TYC 6248 291 1.
Additional R band and low resolution spectroscopy images were taken during the same observing session. These observations will be reported as soon as they are reduced.
Regards, Doug West Mulvane, KS, USA
Based on color correction made available by the Rc band image the earlier V band magnitude estimate of the possible nova in Oph has been revised to the following:
1/26/02 V = 9.19 +/- 0.05, 12:39 UT Rc = 8.67 +/- 0.07, 12.44 UT Comparison stars: TYC 6248 1077 1, V = 9.94, B-V = .573, Rc = 9.63 TYC 6248 794 1, V = 9.77, B-V = .166, Rc = 9.68 The Rc magnitudes are derived from the B-V color of the star. The estimated error in Rc relative to V is 0.03 mag. The check star used was TYC 6248 291 1, V = 10.43, B-V = 1.00, Rc = 9.88. MIRA software was used in the reduction of the magnitudes.I forgot to mention this in an earlier e-mail, I compared the image of the field to SERC DSS1/ST5c1 plate and the object is not present on the DSS plate.
Regards, Doug West
2002 01 27.840 UT (4 frames) R.A. = 17h37m34s.36 Decl. = -16o23'18".4 (equinox 2000.0) 12 reference stars from GSC-ACT. Mean residuals: 0.14" in R.A., 0.15" in Decl. 0.18-m f/5.5 reflector. K. Kadota, Ageo, Saitama, Japan.Kadota-san's image is accessible at:
Prediscovery observation of Nova Oph 2002 = HadV105
Hirohisa Sato (Sugagawa, Japan) relays that Tsutomu Seki (Kochi, Japan) recorded the following prediscovery image of the nova (Nova Oph 2002 = HadV105).
2002 Jan. 19.854 (UT) approximate position 17h 37m 32s -16o 23'.5 (J2000.0) photographic mag 8.9 (90mm F3.5 lens)OPHnova2002 20020119.854 89p TSe (T. Seki)
Independent discovery of Nova Oph 2002 = HadV105
Independent discovery was reported by Yuji Nakamura (Mie, Japan), as reported in IAUC 7808.
OPHnova2002 20020124.867 93p Nry
Prediscovery observations of Nova Oph 2002 by H. Nishimura
Hideo Nishimura (Kakegawa, Shizuoka, Japan) reports the following prediscovery positive observation of Nova Oph 2002 (=HadV105)
object YYYYMMDD(UT) mag code exp OPHnova2002 20020121.85385 85p Nmh.VSOLJ 30s OPHnova2002 20020124.84326 90p Nmh.VSOLJ 35s Observer's code: Nmh: H. Nishimura Instruments: Pentax 6x7 105mm f/5 T-Max 400The data are relayed from Yoichi Muraoka (Hamamatsu, Japan)
On 1/26/02 12:52 UT three low-resolution spectra of the potential nova in Oph were taken with a nonobjective slitless spectrometer. Thin clouds were present and the sky was becoming light due to the approaching dawn. The sky conditions and the relative faintness of the object (V=9.2) resulted in a low signal to noise ratio of ~3 for each spectrum. The spectrometer consists of a transmission grating, an 0.2 m SCT, and a SBIG ST-8 CCD camera. The wavelength is calibrated relative to A type stars. The standard deviation of wavelength measurement is approximately 25 Angstrom.
All three spectra contained an emission peak at an average wavelength of 6598 Angstrom. This peak is within two standard deviations of the H alpha peak at 6562.81 Angstrom. From this measurement, I conclude that the new object in Oph does exhibit H alpha emission.
Regards, Doug West Mulvane, KS, USA(vsnet-discovery-nova 35)
The following message was recently sent to CBAT:
A. Retter, S. O'Toole, University of Sydney; R. Stathakis, J. Pogson, AAO; T. Naylor, Exeter University, report: We observed the possible nova Oph 2002=HadV105 (IAUC 7808) with the 3.9-m AAT telescope (+RGO) in January 26, 18:30 UT. Preliminary analysis of the medium resolution spectra (400-700nm) shows that they are dominated by strong emission lines and possibly weak P-Cygni profiles. The strongest lines are H-alpha, H-beta and Fe II multiplets 42, 74, 48, 49, 55 etc. The FWZI of the H-alpha and H-beta lines is 2350+/-100 km/s. The object is, therefore, very likely a classical nova than belongs to the Fe II class, caught at the early decline phase.
Spectra of this nova, taken by K. Ayani (Bisei Astronomical Observatory), are presented at the following URLs. Most of emission lines are Balmer and Fe II lines.
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