(CCD image by Berto Monard)
(CCD image by Greg Bolt)
(Image by Paulo Cacella and the DSS image)
Possible Nova in Ophiuchus
Akira Takao (Kitakyushu, Japan) reports the detection of a likely new object on his two unfiltered CCD images taken on July 10 and 16. The reality of the object was confirmed on multiple CCD images taken with different image centers. Takao's observations are summarized as below (the object's name is tentatively assigned here):
object YYYYMMDD(UT) mag code OPHnova2003? 20010418.806 <126C Toa.VSOLJ OPHnova2003? 20020318.808 <116C Toa.VSOLJ OPHnova2003? 20020512.647 <116C Toa.VSOLJ OPHnova2003? 20030418.812 <116C Toa.VSOLJ OPHnova2003? 20030710.598 114C Toa.VSOLJ OPHnova2003? 20030716.523 112C Toa.VSOLJThe magnitude were derived from GSC 6833.117, GSC 6833.89, GSC 6833.101. The instruments were f120mm F4 Telephotolens, ST-8, unfiltered.
Takao reports the approximate position of the object (maximum 20 arcsec uncertainty) as follows:
17h 19m 14s.4 (J2000.0) -27o 22' 37"There is no bright 2MASS star nor an IRAS source.
According to ASAS-3 public data, this object was recorded to brighten on June 15. After maintaining magnitudes of V=11.0-11.5, the object apparently reached a maximum of V=10.6 on June 26. The corresponding part is shown below. [The dates have been corrected from the original posting].
HJD-2450000 V error ======================== 2805.68946 11.212 0.061 ASAS-3 outburst detection 2809.71132 10.813 0.048 2809.82674 11.340 0.024 2810.63091 11.426 0.088 2810.83013 11.551 0.047 2811.69979 11.452 0.023 2812.63353 11.077 0.047 2812.84579 11.077 0.023 2813.80357 10.902 0.048 2816.83935 10.591 0.022 maximum? 2819.68174 10.799 0.077 2821.58933 10.880 0.039 2833.60945 11.704 0.054 2833.63153 11.647 0.077 2834.72946 11.550 0.042 2836.58633 11.306 0.066The last ASAS-3 negative detection was about 11 days before this initial detection, but this negative detection should be treated with caution because ASAS-3 may have simply failed to pick up the object. Prior to the present outburst, there was no indication of meaningful detection by ASAS-3 in the past.
The similarity of the V-band and unfiltered CCD magnitudes indicate that the object is not a red variable. The light behavior suggests some sort of an eruptive object such as a nova.
Spectroscopic confirmation as well as precise astrometry is very urgently requested to reveal the nature of the object.
Regards, Taichi Kato(vsnet-discovery-nova 217)
Date: Thu, 17 Jul 2003 17:26:28 +1000 From: Vello Tabur
Subject: Re: [vsnet-newvar 2054] Possible Nova in Ophiuchus
Oops! I first detected this object in the course of my own survey on June 16 but mistook it for a variable. I even assigned a number for it in my own catalog of variables that I can detect with my equipment! I took numerous images when I first noticed it (waiting for it to move; hoping for a comet) but when it didn't, I catalogued it and moved on especially since it was visible (but much fainter) on previous images. Here is a list of prediscovery observations using an unfiltered 140mm f/2.8 telephoto lens + ST8.
YYYYMMDD JD CCD-R 20030321 2452720.10023 12.9 20030405 2452735.15183 13.1 20030429 2452759.07862 13.2 20030504 2452764.06586 13.1 20030510 2452770.03739 13.1 20030522 2452782.16690 13.0 20030529 2452789.09510 12.6 20030616 2452807.03354 10.1 20030616 2452807.04613 10.2 20030616 2452807.06032 10.3 20030616 2452807.08168 10.3 20030616 2452807.10305 10.1 20030705 2452826.07376 9.8An updated position based on my images is 17h 19m 14s.2 -27d 22' 34" (+/- 5") J2000
-- Vello Tabur Comet Hunting Techniques http://www.tip.net.au/~vello R&D, SearchSoftwareAmerica http://www.searchsoftware.com
Regards, Taichi Kato(vsnet-discovery-nova 220)
I just visually confirmed this new object. Comp stars were TYC6833-0286-1 (V=10.65) and TYC6833-0078-1 (V=11.22) magnitudes from Tycho2+Bessell corrections.
N?OPH 20030717.4430 10.8 LMK
Mike Linnolt Honolulu, HI(vsnet-discovery-nova 221)
Date: Thu, 17 Jul 2003 20:33:48 -0400 From: "W.Liller"Here is what I can tell you about the possibile nova in Oph:
Subject: Possible nova in Oph Hola Taichi -
object YYYYMMDD(UT) mag code OPHnova2003? 20030607.117 <11.1R LIL OPHnova2003? 20030623.132 10.4R LIL OPHnova2003? 20030714.985 11.1R LILAll observations were with Kodak TP film, an orange filter, and an 85mm f/1.5 Nikon lens. Uncertainties +/- 0.2 mags.
All the best, Bill Liller
The probable Nova was imaged at the Bronberg Observatory with the unfiltered CCD camera.
In comparison to the image from the DSS-2/red, a new and bright object showed on the image. Astrometry traceable to the UCAC1 frame gives (2000) coordinates:
17 19 14.10 -27 22 35.4 (+/- 0.2" estimated)
The unfitered CCD observation (UT) :
Nova Oph03 20030717.821 10.4CR (UCAC1 reference)
Note: compared to the recent estimate by M Linnolt, this CR magnitude confirms the new star as non-red.
Berto Monard Bronberg Observatory / CBA Pretoria
Hola everyone -
Last night, July 18.15 UT, through thin clouds, I was able to get a CCD objective grating spectrogram of the possible nova in Ophiuchus. H-alpha is present and strong in emission, some 12 times the intensity of the surrounding continuum. Its FWHM = 1450 km/sec.
Here is what I have for the magnitudes:
object YYYYMMDD(UT) mag code comments
OPHnova2003 20030607.117 <11.1R LIL Red photographic* OPHnova2003 20030623.132 10.4R LIL Red photographic* OPHnova2003 20030714.985 11.1R LIL Red photographic* OPHnova2003 20030718.114 11.29V LIL CCD through clouds, +/- 0.07 mag OPHnova2003 20030718.116 12.13B LIL CCD through clouds, +/- 0.07 magThus, the nova has a B-V of approximately +0.8.
All the best to all, Bill Liller
* Made with Kodak TP film, an orange filter, and an 85mm f/1.5 Nikon lens.
Uncertainties +/- 0.2 mags.
VSOLJ news 107
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