NOT and LT spectroscopic classification of supernovae Gaia15acz and Gaia15aek

ATel #7378; S. Mattila, J. Harmanen, T. Kangas (University of Turku), A. S. Piascik, C. Davis, I. A. Steele (Liverpool John Moores University), N. Blagorodnova, M. Fraser, H. Campbell, S. Hodgkin, N. Walton (University of Cambridge), L. Wyrzykowski (Warsaw University Observatory), E. Kankare, R. Kotak (Queen's University Belfast)
on 13 Apr 2015; 11:49 UT
Credential Certification: Seppo Mattila (seppo.mattila@utu.fi)

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We report the spectroscopic classification of supernova Gaia15acz based on a low-resolution spectrum obtained on 2015 Apr. 12.0 UT with the Nordic Optical Telescope (+ ALFOSC; range 320-910 nm) and supernova Gaia15aek based on low-resolution spectra obtained on 2015 Apr. 9.9 UT with the Liverpool Telescope (+ SPRAT; range 400-800 nm) and on Apr. 11.9 UT with the Nordic Optical Telescope (+ ALFOSC; range 320-910 nm).

Gaia15acz and Gaia15aek were discovered by the Gaia Photometric Science Alerts programme at magnitudes of 18.0 and 17.7 on 2015 Mar. 12.8 UT and Mar 30.1 UT, respectively. Gaia15acz is located ~1.8 arcsec from the centre of the galaxy SDSS J091101.47+344427.1 and Gaia15aek ~9.7 arcsec from the centre of MCG +11-09-010. The Gaia low-resolution BP and RP spectra indicated a Type II supernova classification for both objects.

 
Name             | RA (J2000)   | Dec (J2000)  | Disc. Date | Disc Mag | z     | Type    | Phase              | Notes 
 
Gaia15acz        | 09:11:01.62  | +34:44:27.2  | 2015-03-12 | 18.0     | ~0.018| SN II   | ~2 months past max | (1) 
Gaia15aek        | 06:47:02.70  | +64:56:03.7  | 2015-03-30 | 17.7     | ~0.012| SN II   | ~2 weeks past max  | (2) 

(1) Best match found with the Type II-P SN 2012A at ~2 months after the max. light.

(2) Matches found with several Type II-P SNe a couple of weeks after the max. light.

The classifications were done with GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024). We acknowledge ESA Gaia (http://cosmos.esa.int/gaia), and the DPAC Photometric Science Alerts Team (http://gaia.ac.uk/selected-gaia-science-alerts) (Rixon et al, 2014, ATel #6593).