TCP J17525020-2024150 2023 07 15.4590* 17 52 50.20 -20 24 15.0 10.3 U Sgr 4 0
2023 07 15.4590
Discovered by Andrew Pearce, Nedlands, Western Australia, who found this star on three images (limit mag.= 12.0) taken with Canon 800D digital camera + 85-mm f/1.2 lens, writes nothing is visible at the discovery position on three images taken on 2023 July 14.457 UT or July 12.455 UT with the same instrument. Star was visually confirmed on July 15.498 UT at magnitude 10.3. Position is approximate.
2023 07 15.5390
Position end figures 49s.30, 15".5 measured with 0.35m R-COP reflector + CCD at Perth Observatory, W. Australia. J2000, Gaia DR2 positions. Position appears to correspond to an 18.9 G magnitude star (Gaia DR3 4118800145787192064) which appears to be the same as a 20.5 G magnitude star measured in Pan-STARRS PS1 survey (Star ID 83512682054115201). Photometry using R-COP as follows: July 15.539 UT V = 10.24 and B = 11.73. Andrew Pearce, Nedlands, W. Australia.
2023 07 15.5215
Yuji Nakamura, Kameyama, Mie, Japan reports his independent discovery (by e-mail to National Astronomical Observatory of Japan on Jul. 15.6875 UT) of this object. It is caught in 4 frames (6 seconds exposure) at mag about 9.6 (limiting mag about 13.0) using f.l. 135-mm F/4.0 lens + CMOS camera. Position end figures 49s.26, 14".3. It was not detected on the images (limiting mag about 12.5) taken with the same instruments on Jul. 11.4758 UT. (H. Yamaoka, NAOJ)
2023 07 14.7775
The transient is visible on unfiltered pre-discovery images obtained with two CCD cameras attached to identical 135mm f/2.0 telephoto lenses: 2023-07-14.7775 UTC CV=13.5 +/-0.1 (SBIG ST-8300M); 2023-07-14.7929 UTC CV=13.1 +/-0.2 (SBIG STL-11000M). ---- Stanislav Korotkiy, Kirill Sokolovsky, Sergei Ostapenko
2023 07 15.6422
Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Sgr (TOCP Designation: TCP J17525020-2024150) we performed some follow-up of this object through a TEL 0.1-m f/3.56 astrograph + CMOS located in Yass, North South Wales in Australia and operated by Telescope Live network (MPC code Q56). On images taken on July 15.5, 2023 we can confirm the presence of an optical counterpart with L-filtered CMOS magnitude +10.5 at coordinates: R.A. = 17 52 49.30, Decl.= -20 24 15.6 (equinox 2000.0; UCAC4 catalogue reference stars for astrometry). Our confirmation image: https://tinyurl.com/novasgr - An animation showing a comparison between our image and an archive POSS plate: https://tinyurl.com/novasgranim ---- Ernesto Guido, Marco Rocchetto, Adriano Valvasori
2023 07 15.591
Further photometry using 0.43m reflector + CCD at Siding Spring, NSW (T17) as follows: July 15.591 UT B = 12.08, V = 10.29, R = 9.07 and I = 8.12. Visual magnitude estimates: July 15.528 UT 10.3 and July 15.583 UT 10.4. Andrew Pearce, Nedlands, Western Australia.
2023 07 16.018
Further photometry using 0.50m reflector + CCD at Rio Hurtado Valley, Chile (T72) as follows: July 16.018 UT B = 12.77, V = 11.37, R = 9.78 and I = 8.40. Andrew Pearce, Nedlands, Western Australia.
2023 07 15.4590
The transient coincides with the candidate magnetic cataclysmic variable IGR J17528-2022 - see the Chandra position and optical finder chart reported by Hare et al. (2021, ApJ, 914, 85) https://ui.adsabs.harvard.edu/abs/2021ApJ...914...85H/abstract ---- Kirill Sokolovsky
2023 07 16.3048
Phomometry results were B=11.97, V=10.94, Rc=9.58 and Ic=8.35 with with T72, iTelescope.NET (0.5m, F:6.8 CDK) at Deep Sky Chile at Rio Hurtado Valley, Chile. https://meineko.com/ccd/TCP_J17525020-2024150.jpg - Seiichiro Kiyota (Kamagaya, Japan)
2023 07 16.469
Further photometry using 0.43m reflector + CCD at Siding Spring, NSW (T17) as follows: July 16.469 UT B = 13.37, V = 11.79, R = 10.06 and I = 8.81. Visual magnitude estimates: July 16.462 UT 11.9. Andrew Pearce, Nedlands, Western Australia.
2023 07 16.8603
This transient was observed on 2023 07 16.8603 by Gianluca Masi, remotely using the 14” robotic unit part of the Virtual Telescope Project facility in Manciano, Italy. R-filtered images show a source at mag. 9.4 (R mags for the reference stars from UCAC-4). We also performed astrometry, getting the following end figures: 49.31s; 15”.6 (J2000.0, mean residuals of 0.15" on both axes).
2023 07 16.8603
For the above,I've used a CCD camera coupled to the mentioned 14” telescope. Gianluca Masi
2023 07 16.867
On July 16.867, a low resolution spectrum was collected by Gianluca Masi with the same 14” (356mm) telescope mentioned above, using a 200 lines/mm grating (dispersion about 1,7 nm/pixel). This spectrum clearly shows a very strong H-alpha emission at 656.3 nm.