ASAS-SN Discovery and Spectroscopic classification of Two Supernovae in UGC 05566 and SDSS J111840.97+250958.5

ATel #6196; A. B. Davis, R. M. Wagner (Ohio State), A. Kaur, A. Porter (Clemson), A. Wilber (ASU), J. L. Prieto (Princeton), T. W.-S. Holoien, B. J. Shappee, K. Z. Stanek, C. S. Kochanek, J. Jencson, U. Basu, J. F. Beacom (Ohio State), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), J. Brimacombe (Coral Towers Observatory), D. Bersier (LJMU), C. E. Woodward (Minnesota), S. G. Starrfield (ASU), D. Hartman (Clemson)
on 2 Jun 2014; 21:03 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Benjamin Shappee (shappee@astronomy.ohio-state.edu)

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During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii, we discovered two new transient sources, both supernovae, in the outskirts of UGC 05566 and in SDSS J111840.97+250958.5.

 
Object       RA (J2000)     DEC (J2000)      Disc. UT Date   Disc. V mag 
ASASSN-14bt  10:19:19.96    +58:30:15.42     2014-05-27.28      17.1    
ASASSN-14bu  11:18:41.03    +25:09:59.88     2014-05-29.31	17.1 

ASASSN-14bt was discovered in images obtained 2014 UT May 27.28 at V~17.1 mag. We also detect the object in images obtained on May 31.28 with a magnitude V~16.5 and on June 1.26 with a magnitude V~16.4. We do not detect this object in images taken on 2014 UT May 23.27 and before. This figure shows the ASAS-SN reference image (top left), archival SDSS g-band image (top right), ASAS-SN May 27.28 discovery subtraction image (bottom left), and the ASAS-SN June 1.26 confirmation image (bottom right). The green circle has a radius of 7.0" at the position of the SN.

ASASSN-14bt is approximately 2.6" North and 2.9" West of the core of UGC 05566 (z=0.0289, d=124 Mpc, via NED), which would give it an absolute V mag of approx. -19.09 in the latest epoch (m-M=35.46 A_V=0.026 Schlafly & Finkbeiner 2011).

ASASSN-14bu was discovered in images obtained 2014 UT May 29.31 at V~ 17.1 mag. We also detect the object in images obtained on June 1.32 and June 2.28. We do not detect this object in images taken on 2014 UT May 22.32 and before. This figure shows the ASAS-SN reference image (top left), archival SDSS g-band image (top right), ASAS-SN May 29.31 discovery subtraction image (bottom left), and the ASAS-SN June 1.32 confirmation image (bottom right). The green circle has a radius of 3" at the position of the SN.

ASASSN-14bu is approximately 1.3" North and 0.7" East of the core of SDSS J111840.97+250958.5 (z=0.0254, d=111 Mpc, via NED), which would give it an absolute V mag of approx. -18.2 (m-M=35.23 A_V=0.044 Schlafly & Finkbeiner 2011).

We obtained optical spectra of ASASSN-14bt and ASASSN-14bu with the MDM 2.4m + OSMOS (range 4000-6850 Angs., res. 3 Angs.) on UT June 2.2. The spectrum of ASASSN-14bt shows characteristics of a Type Ia SN around maximum light, with a red continuum indicating high host-galaxy extinction. After correcting for the redshift of the host galaxy, we measure the blueshifted velocity of the Si II 6355 line at -10900 km/s. The spectrum of ASASSN-14bu shows a blue continuum with a possible weak detection of H-alpha, which indicates a young Type II SN.

Follow-up observations of both sources are encouraged.

We thank LCOGT and its staff for their continued support of ASAS-SN. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.