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TCP J18102829-2729590: possible nova (10.7 mag) in Sagittarius

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SPK's picture
TCP J18102829-2729590: possible nova (10.7 mag) in Sagittarius

TCP J18102829-2729590 (N:)

Discoverer: Koichi Itagaki (Yamagata, Japan)

R.A. 18h10m28.29s Decl. -27°29'59.0" (J2000.0)
2016 Oct. 20.3828 UT, 10.7 mag (CCD, unfiltered)

Two Initial Gaia Source List stars (of 20 mag) are less than 1" from the reported position.

Spectroscopy is urgently required.

Clear skies,

SPK's picture
Discovery details and CCD image

Discovered by K. Itagaki, Yamagata, Japan using 180-mm f/4.0 lens, who has confirmed this object using 0.60-m f/5.7 reflector immediately. Nothing is visible at this location on a past frame taken on 2016 Oct. 4.447 UT using same 180-mm lens (limit mag.= 13.0). See a CCD image at

Andrew Pearce
Andrew Pearce's picture
TCP J18102829-2729590: possible nova (10.7 mag) in Sagittarius

Hi Patrick and all

I have visually confirmed this nova suspect.  On Oct 20.485UT it was mag 11.0.  I must say modern communications are impressive when you can confirm a possible nova discovery only 2 hours after the original image was taken!

Thanks also to Patrick for alerting us to these discoveries through the Forum and Facebook.  It's much appreciated!


Andrew Pearce (PEX)

Sebastian Otero
Sebastian Otero's picture
Denis detection and companion

There is a DENIS star (DENIS J181028.3-272958) 1" away from the reported position not recorded in other catalogues at Ic= 13.47 on 2450189.909 (April 16, 1996).
It is the brightest detection in the area, 1.4 mag. brighter than the 15.7 Vmag. companion which is 4" to the West.
Observers should be careful with this rather bright companion. Now it doesn't contribute any light to the combined brightness but as the target fades its contribution will become relevant.

If the DENIS detection applies to this nova (better astrometry would help!) then this might be a recurrent nova. Spectroscopic observations are encouraged!


HQA's picture
new transient

We were able to get BVRI images with BSM_South an hour or two ago.  Based on the jpeg image provided by the discoverer, and the comments from Sebastian about close companions, this target is going to be tough.  It is a very crowded field.  To help decide whether the bright Ic object from DENIS is real, and different from the nova candidate, you can use astrometry.  Take images at BVRI and measure the position of the target.  You should see a systematic shift as you go to redder wavelengths if there is a bright red companion.  The BSM images won't be good enough to separate out the nearby stars and provide improved astrometry at any wavelength.


SPK's picture
Follow-up report by Seiichiro Kiyota (Kamagaya, Japan)

2016 10 20.4310 UT
Photometry results were V=10.95 and Ic=10.24 with 0.70-m f/6.6 CDK astrograph + FLI PL09000 CCD, iTelescope @ NSW, Australia remotely. My image is available at

SPK's picture
Classical nova in the optically thick stage (ATel #9658)

Paul Luckas (International Centre for Radio Astronomy Research, Univ. of Western Australia; ARAS Group):
Confirmation of TCP J18102829-2729590 in Sagittarius as a classical nova in the optically thick stage

Andrew Pearce
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TCP J18102829-2729590

Hi All

Looks like we caught TCP J18102829-2729590 on the rise.  A visual obervation made tonight indicates that it appears to have brightened over 1 magnitude in the last 24 hours.  My obs have been uploaded into the AID.


Andrew Pearce (PEX)

hambsch's picture
Observations from Chile


I have taken up this nova in my observig program. Had to choose one additional star not in the sequence list as except one star in the list all others do not have I magnitudes. Observed magnitudes are of 10.25 in V, 9.45 in I and 10.87 in B band.




David Benn
David Benn's picture
Visual observation from Adelaide

I made a visual estimate tonight with my 8" SCT at magnitude 8.0.

Took some images last night with a view towards DSLR photometry, but the nearby star makes this less than ideal.


SPK's picture
OGLE-IV pre-discovery observations (ATel #9683)

Two classical novae located toward the Galactic bulge were recently discovered. Both objects are located in the area that is regularly monitored by the OGLE-IV Survey.

TCP J18102829-2729590 (CBET 4332; ATel #9658) was discovered on 2016 Oct. 20.383 UT. The object is located in the OGLE-IV field BLG519. The star was saturated in the image acquired on 2016 October 20.98993 UT, meaning it was brighter than I=11 mag. The last pre-eruption image was taken on October 14.01912 UT. We measured the equatorial coordinates of the nova of R.A. = 18:10:28.29, Decl. = -27:29:59.3 (J2000.0). The progenitor is undetected in the OGLE deep template image, meaning I > 22 mag. Finding charts can be found here:

SPK's picture
Re: Denis detection and companion

DENIS J181028.3-272958 is 1.0" E and 0.5" N of the position measured by the OGLE team.


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