H-alpha emission from extragalactic nova candidate M81N 2020-07a
ATel #13908; A. Kurtenkov, Z. Donchev (Institute of Astronomy and NAO, Bulgarian Academy of Sciences, Bulgaria)
on 30 Jul 2020; 15:28 UT
Credential Certification: Kiril Stoyanov (kstoyanov@astro.bas.bg)
We report photometric detection of H-alpha emission from the recent nova candidate M81N 2020-07a discovered by Hornoch et al. (ATel #13889).
We imaged M81 in Cousins R and narrowband H-alpha filters with the FoReRo2 focal reducer at the Rozhen 2-meter RCC telescope in Bulgaria. Photometric calibrations were obtained using field stars included in the SDSS DR12 catalog. Their Sloan r and i magnitudes were converted to Cousins R by applying the transformations from Jordi et al. (2006) available on the SDSS webpage. The R magnitudes were used as references for both the R and H-alpha bands with a precision of 0.01 and 0.03 mag respectively. Aperture photometry after subtraction of the M81 galactic background yielded the following magnitudes:
# Date,UT Filter Exposures Magnitude Error
2020-07-24.865 R 3x120s 19.27 0.03
2020-07-24.885 Hα 7x300s 18.16 0.03
The utilized H-alpha filter has a FWHM of 3 nm. The result is consistent with a M81 nova.
Our images were obtained at a 2.0" seeing and sampled at 0.5"/pix. We used a 2.5" radius aperture.
This work was supported by the Bulgarian Ministry of Education and Science under the National Research Programme "Young scientists and postdoctoral students" approved by DCM #577/17.08.2018.
Processed R and H-alpha images of the M81 nova
