SN 2015B in NGC 4782 - 2015 01 05

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SN2015B (ex PSN J12543553-1234186) discovered on 2015 January 05.12293, by S. Leonini, M. Conti, G. Guerrini, P. Rosi and L.M. Tinjaca Ramirez in NGC 4782 (mv 15,0) during an automatic survey of the Italian Supernovae Search Project (telescope 0,53 mt - Osservatorio Montarrenti - Siena). The coordinates of new source are R.A. 12h54m35.53s +/-0.19”, Decl. -12°34'18.6" +/-0.21” UT (Type Ia).

http://www.cbat.eps.harvard.edu/unconf/followups/J12543553-1234186.html

 

CLASSIFICATION ATEL

 

Asiago spectroscopic classification of four SNe

ATel #6899; L. Tomasella, S. Benetti, E. Cappellaro, N. Elias-Rosa, P. Ochner, A. Pastorello, L. Tartaglia, G. Terreran, M. Turatto (INAF OAPd)
on 11 Jan 2015; 06:07 UT
Credential Certification: Lina Tomasella ( Questo indirizzo e-mail è protetto dallo spam bot. Abilita Javascript per vederlo. )

Subjects: Optical, Supernovae

The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observation of ASASSN-15ak, PSN J09411555+3553174, PSN J12543553-1234186, ASASSN-15ae, MASTER OT J021447.67+481852.6. Targets were supplied by the Astronomy Section of the Rochester Academy of Sciences (arXiv:1103.5165) and/or by the CBAT Transient Objects Confirmation Page (TOCP). The observations were performed with the Asiago 1.82 m Copernico Telescope (+AFOSC; range 340-820 nm; resolution 1.2 nm), which was equipped with the CCD Andor IKON L936.

Name | Date (UT) | z | Type | Phase | Notes
ASASSN-15ak | 20150110.87 | 0.015 | SN Ia-pec | pre-max | (1)
MASTER OT J021447.67+481852.6 | 20150110.90 | | star | | (2)
PSN J09411555+3553174 | 20150110.94 | 0.023 | SN Ia | pre-max | (3)
PSN J12543553-1234186 | 20150111.12 | 0.015 | SN Ia | +6d | (4)
ASASSN-15ae | 20150111.17 | 0.031 | SN Ia | +5d | (5)

(1) Best match with type-Ia pec 91T-like SNe, few days before B-band maximum light. The expansion velocity of ASASSN-15ak, as deduced from the position of the minimum of the Si-II 635.5nm absorption, is around 11000 km/s.

 

(2) The spectrum shows Balmer absorptions (Hbeta, Hgamma, Hdelta), at rest wavelength, on a strong blue continuum. We note a weak emission component in the red wing of Balmer lines. Weak NaID absorption is also visible.

(3) A good match is found with several normal type-Ia supernovae few days before B-band maximum light. The expansion velocity of PSN J09411555+3553174, as deduced from the position of the minimum of the Si-II 635.5nm absorption, is around 12200 km/s.

(4) The spectrum shows this is a type-Ia SN around one week after B-band maximum light. The expansion velocity of PSN J12543553-1234186, as deduced from the position of the minimum of the Si-II 635.5nm absorption, is around 10800 km/s.

(5) Best match with several type-Ia SNe, about one week after B-band maximum. The expansion velocity of ASASSN-15ae, as deduced from the position of the minimum of the Si-II 635.5nm absorption, is around 11200 km/s. The classification is in agreement with ATel #6897.

Classification was done with GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024). The Asiago classification spectra are posted at the website http://sngroup.oapd.inaf.it.