Electronic Telegram No. 4955 Central Bureau for Astronomical Telegrams Mailing address: Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau at eps.harvard.edu (alternate cbat at iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network
V1710 SCORPII = NOVA SCORPII 2021 = PNV J17091000-3730500 Paul Camilleri, Katherine, Northern Territory, Australia, reports his discovery of an apparent nova (mag 9.5) on three 5-s exposures taken on Apr. 12.7625 UT with a Nikon D3200 digital SLR camera (+ 85-mm-f.l. f/2 lens), noting the variable to have an orange color; the approximate position was given as R.A. = 17h09m50s, -37d30’50” (equinox J2000.0). The variable was given the provisional designation PNV J17091000-3730500 automatically when it was posted to the Central Bureau’s TOCP webpage. R. Fidrich, Budapest, Hungary, provides position end figures 08s.11, 40″.9 measured on a B-band CCD image obtained on Apr. 12.814 with an iTelescope 0.50-m f/6.8 reflector located at Siding Spring, NSW, Australia. F. Kugel, Banon, France, measured position end figures 08s.32, 42″.6 from three stacked 30-s CCD images taken with a 195-mm-f.l. f/2.8 lens on Apr. 13.12. A. Pearce, Nedlands, W. Australia, provides position end figures 08s.10, 40″.9 from a CCD image obtained remotely on Apr. 13.632 with a 0.43-m f/6.8 reflector located at Siding Spring (reference stars from the Gaia DR2 catalogue). Additional digital-image magnitudes (unfiltered unless noted otherwise) that have been reported for PNV J17091000-3730500: Apr. 11.395 UT, [16.8 (All-Sky Automated Survey for Supernovae; communicated by P. Schmeer, Saarbruecken-Bischmisheim, Germany); 11.682, [13.8 (R. McNaught, Coonabarabran, NSW, Australia; 59-s exposure with Canon 6D camera + 135-mm-f.l. f/2.8 lens); 11.758, [12 (Camilleri); 11.794, [13.5 (McNaught); 12.168, g = 11.1 (ASAS-SN; independent discovery reported by Schmeer; position end figures 08s.11, 40″.4); 12.408, g = 10.4 (ASAS-SN; Schmeer); 12.55, 9.5 (R. Kaufman, Bright, Vic., Australia; green channel approximating V band, Canon 800D camera + 200-mm-f.l. lens; image posted via the following URL https://tinyurl.com/4t5akzyy); 12.583, 9.6 (McNaught); 12.687, 9.5 (McNaught); 12.796, 9.4 (McNaught); 12.814, B = 10.64 (Fidrich; the variable was very red, with B-V being at least +1.5); 12.955, R = 8.03 (V. Agnihotri, Kota, Rajasthan, India; communicated via E. O. Waagen, AAVSO); 12.965, I = 7.09 (Agnihotri); 12.972, V = 8.84 (Agnihotri); 13.12, 8.9 (Kugel); 13.372, B = 9.71 (J. Backman, Lappeenranta, Finland; via Waagen); 13.422, B = 10.05 (J.-F. Hambsch, Mol, Belgium; via Waagen); 13.423, I = 6.74 (Hambsch); 13.424, V = 8.69 (Hambsch); 13.632, V = 8.53 (Pearce); 13.633, B = 10.32 (Pearce); 13.634, I = 6.58 (Pearce); 13.787, 8.5 (F. Romanov, Yuzhno-Morskoy, Nakhodka, Russia; from five stacked 5-s exposures taken with a Canon EOS 60D camera + 135-mm-f.l. f/5.6 lens at ISO 6400 with a hazy sky; image posted at website URL https://www.flickr.com/photos/filipp-romanov/51114244018). Visual magnitude estimates for PNV J17091000-3730500: Apr. 13.068 UT, 8.8 (A. Amorim, Florianopolis, Brazil; via Waagen); 13.128, 8.9 (L. Araujo, Pelotas, Brazil; via Waagen); 13.342, 8.7 (Amorim); 13.715, 8.8 (C. Wyatt, Walcha, NSW, Australia; via Waagen); 13.732, 8.8 (Pearce). Waagen also informs the Bureau that Joshi et al. have reported that their spectroscopy obtained on Apr. 12.916 UT with the Mt. Abu PRL 1.2-m telescope (range 440-900 nm, resolutions about 500 and 2000) show this to be an “Fe II”- type of classical nova caught early in its outburst, with H-alpha, H-beta, Fe II, and O I lines showing P-Cyg profiles on a red continuum (details are given at website URL https://www.astronomerstelegram.org/?read=14544). E. Kazarovets informs the Central Bureau that the permanent GCVS designation V1710 Sco has been given to this nova.
NOTE: These ‘Central Bureau Electronic Telegrams’ are sometimes superseded by text appearing later in the printed IAU Circulars.
We examine the astrometry and photometry of globular star cluster M13 using Gaia EDR3 and ATLAS catalogs. The Gaia EDR3 catalog is for astrometry and ATLAS catalog is for high precession differential photometry. The software Tycho 8.0 supports both the catalogs upto +22.0 magnitudes. If stars are well resolved (imaged at higher focal length), the results will be promising.
Image: Object: M13 DATE-OBS: 2021-03-27T20:56:25.69 EXPTIME: 1320.00 (seconds) SUBFRMS: 22 OBJCTRA: 16 41 46.016 OBJCTDEC: +36 27 13.50 Instrument: Catalog: Gaia EDR3 + ATLAS Bessell (B): +*.*, Bessell (V): +*.* Bessell (R): +*.*, Bessell (I): +*.* CCD: ATIK-383L+ FILTERS: R TELESCOPE: C11, 1623.0mm PRiSMv10, Tycho Site: ORIGIN: Cepheid Observatory, India, Vorion Scientific, India SITELAT: +24:55:00:00 SITELONG:+75:33:58:99 Observers: V.K.Agnihotri, B. Kumar, S. Mahawar, K.Vora Remark: High Moon, Sky Clear. End
The offline variant, “GRAPPA”, was developed by Marc Serrau. Please also include the following acknowledgements if using the catalog in a published paper:
Acknowledgements:
Marc Serrau
ESA GAIA Mission as GRAPPA3 has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).
The acknowledgements for ALTAS catalog, to be used when publishing a paper, are as follows: This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. ATLAS is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, and the South African Astronomical Observatory.
References: Tonry, J.L., Denneau, L., Flewelling, H., Heinze, A.N., Onken, C.A., Smartt, S.J., Stalder, B., Weiland, H.J., Wolf, C. (2018). “The ATLAS All-Sky Stellar Reference Catalog.” Astrophys. J. 867, A105. Kostov, A., Bonev, T. (2017). “Transformation of Pan-STARRS1 gri to Stetson BVRI magnitudes. Photometry of small bodies observations.” Bulgarian Astron. J. 28, 3 (AriXiv:1706.06147v2).
Asteroid photometry is nothing but the study of fraction of solar radiation, which is reflected by the surface of small body. Here we examined the photometry of Apophis, a big/elongate metal rich asteroid passing by near to earth.
If we assume that asteroid Apophis is metal rich, it could reflect good part of solar radiation at V band as well as R Band. The tendency of photon reflection decrease from V (short wavelengths) to R (longer wavelengths) band. Here we took the assumption that sun is G2V type star, so most of photons are towards yellow + red end and hence small body is reflecting more photons at R band. These are just assumption to make task interesting. Anyway!
The second point is that if asteroid is perfect spherical body, spinning around random axis will reflect same flux towards telescope, but case will be different if small body have irregular structure. In this case the flux reflected will be proportional to the cosine of area seen by telescope and depend on angle between sun/asteroid/earth.
In our study, we dragged the R band flux w.r.t time. The FITS generated and examined using PriSMv10 batch photometry using UCAC4 catalog. The results are shown below.
Apophis Photometric Curve
We should not forget that Apophis photometric curve was measured w.r.t standard stars and as soon as sun and asteroid changes the position in sky, the incident solar flux does not remain constant. It can be seen that the magnitude at the end of observation goes too high.
Instrument: Catalog: UCAC4 Bessell (B): +*.*, Bessell (V): +*.* Bessell (R): +15.2, Bessell (I): +*.* CCD: ATIK-383L+ FILTERS: R TELESCOPE: C11, 1623.0mm PRiSMv10, Astrometrica Site: ORIGIN: Cepheid Observatory, India, Vorion Scientific, India SITELAT: +24:55:00:00 SITELONG:+75:33:58:99 Observers: V.K.Agnihotri, B. Kumar, S. Mahawar, K.Vora Remark: Sky Clear. End
