Independent Discovery of a Probable Nova in M81

ATel #11465; H. Kucakova, K. Hornoch (Ondrejov), S. C. Williams (Lancaster), M. Henze (SDSU), G. Sala, J. Jose (UPC-IEEC), H. Meusinger (TLS), M. J. Darnley (LJMU), A. Kaur, D. H. Hartmann (Clemson), A. W. Shafter (SDSU)
on 22 Mar 2018; 20:59 UT
Credential Certification: Steven Williams (scw@astro.ljmu.ac.uk)

Tweet

The M81 nova monitoring collaboration reports the independent discovery of a probable nova in M81 on a co-added 1350-s unfiltered CCD frame taken on 2018 Mar. 21.952 UT with the 0.65-m telescope at Ondrejov. The object is visible on several prediscovery images taken with the 0.65-m telescope at Ondrejov (OND), the 0.80-m telescope Joan Oro at the Observatori Astronomic del Montsec (TJO) and The Liverpool Telescope at La Palma (LT). We find an increasing Hα excess, which supports the transient being a nova eruption.

The object was first announced and designated AT2018akh by Z. Xu and X. Gao (see here) and is located at R.A. = 9h55m13s.53, Decl. = +69o00'48".1 (equinox 2000.0), which is 105.4" west and 187.0" south of the center of M81 (see link to discovery image below).

Here we list the observing dates and corresponding photometry:

 
  Date [UT]    |  Mag  | Err  | Filter  | Telescope 
 
2018-03-11.816 | <21.6 |      | C       | OND  
2018-03-15.949 |  20.6 | 0.4  | R       | TJO  
2018-03-16.877 |  20.5 | 0.5  | R       | TJO 
2018-03-16.942 |  20.3 | 0.2  | Hα      | LT 
2018-03-16.951 |  20.5 | 0.1  | r       | LT 
2018-03-18.851 |  21.1 | 0.25 | C       | OND 
2018-03-18.883 | <21.6 |      | R       | TJO 
2018-03-21.930 |  19.9 | 0.1  | Hα      | LT 
2018-03-21.939 |  21.1 | 0.2  | r       | LT 
2018-03-21.952 |  20.4 | 0.2  | C       | OND 
2018-03-22.146 |  20.7 | 0.2  | C       | OND 
 
 

The OND 0.65-m is a reflecting telescope at the Ondrejov observatory operated jointly by the Astronomical Institute of ASCR and the Astronomical Institute of the Charles University of Prague, Czech Republic. It uses a Moravian Instruments G2-3200 CCD camera (with a Kodak KAF-3200ME sensor and standard BVRI photometric filters) mounted at the prime focus. The Telescopi Joan Oro (TJO) is a 80-cm Ritchey-Chretien F/9.6 telescope at the Observatori Astronomic del Montsec, owned by the Catalan Government and operated by the Institut d'Estudis Espacials de Catalunya, Spain. It uses a Finger Lakes PL4240-1-BI CCD Camera with a Class 1 Basic Broadband coated 2k x 2k chip with 13.5 microns square pixels. The LT (Steele et al. 2004) is a fully robotic 2-m telescope operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. Our observations use the IO:O optical CCD camera of the LT. The unfiltered OND photometry was calibrated against R-band comparison stars from Perelmuter & Racine (1995). The TJO and LT photometry is based on the SDSS DR7 photometry catalogue.

Discovery image