V2540 Oph = Nova Oph 2002 = HadV105

(Haseda's discovery photograph)

(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:

ftp://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Novae/hadv105/

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)

Confirmation

(vsnet-discovery-nova 28)

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

(vsnet-discovery-nova 30)

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

Astrometry by K. Kadota

(vsnet-discovery-nova 36)

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:

http://www.astroarts.com/ageo/nova/NovaOph2002/NovaOph2002-20020127.jpg

Prediscovery observation (Seki) and independent discovery (Nakamura)

(vsnet-discovery-nova 31)

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)

Seki's image

(vsnet-discovery-nova 32)

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

(vsnet-discovery-nova 34)

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 400

The data are relayed from Yoichi Muraoka (Hamamatsu, Japan)

Spectroscopic confirmation

(vsnet-discovery-nova 29)

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.

Spectroscopy at Bisei Astronomical Observatory

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.

http://www.town.bisei.okayama.jp/bao/astro/nova/nova_oph2002spim.gif
http://www.town.bisei.okayama.jp/bao/astro/nova/nova_oph2002sppl.gif