Abstract
We present the results of the spectroscopic and photometric monitoring campaign of ASASSN- 15ed. The transient was discovered quite young by the All Sky Automated Survey for Super- Novae (ASAS-SN) survey. Amateur astronomers allowed us to sample the photometric SN evolution around maximum light,which we estimate to have occurred on JD=2457087.4±0.6 in the r band. Its apparent r-band magnitude at maximum was r = 16.91 ± 0.10, providing an absolute magnitude Mr ≈-20.04 ± 0.20, which is slightly more luminous than the typical magnitudes estimated for Type Ibn SNe. The post-peak evolution was well monitored, and the decline rate (being in most bands around 0.1 mag d-1 during the first 25 d after maximum) is marginally slower than the average decline rates of SNe Ibn during the same time interval. The object was initially classified as a Type Ibn SN because early-time spectra were characterized by a blue continuum with superimposed narrow P-Cygni lines of He I, suggesting the presence of a slowly moving (1200-1500 km s-1), He-rich circumstellar medium. Later on, broad P-Cygni He I lines became prominent. The inferred velocities, as measured from the minimum of the broad absorption components, were between 6000 and 7000 km s-1. As we attribute these broad features to the SN ejecta, this is the first time we have observed the transition of a Type Ibn SN to a Type Ib SN.
Original language | English (US) |
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Pages (from-to) | 3649-3661 |
Number of pages | 13 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 453 |
Issue number | 4 |
DOIs | |
State | Published - Nov 11 2015 |
Keywords
- Supernovae: general
- Supernovae: individual: ASASSN-15ed
- Supernovae: individual: SN 1991D
- Supernovae: individual: SN 2006jc
- Supernovae: individual: SN 2010al
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science