TY - JOUR
T1 - The Low-luminosity Type IIP Supernova 2016bkv with Early-phase Circumstellar Interaction
AU - Nakaoka, Tatsuya
AU - Kawabata, Koji S.
AU - Maeda, Keiichi
AU - Tanaka, Masaomi
AU - Yamanaka, Masayuki
AU - Moriya, Takashi J.
AU - Tominaga, Nozomu
AU - Morokuma, Tomoki
AU - Takaki, Katsutoshi
AU - Kawabata, Miho
AU - Kawahara, Naoki
AU - Itoh, Ryosuke
AU - Shiki, Kensei
AU - Mori, Hiroki
AU - Hirochi, Jun
AU - Abe, Taisei
AU - Uemura, Makoto
AU - Yoshida, Michitoshi
AU - Akitaya, Hiroshi
AU - Moritani, Yuki
AU - Ueno, Issei
AU - Urano, Takeshi
AU - Isogai, Mizuki
AU - Hanayama, Hidekazu
AU - Nagayama, Takahiro
N1 - Funding Information:
K.M. acknowledges support provided by Japan Society for the Promotion of Science (JSPS) through KAKENHI Grant 17H02864.
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved.
PY - 2018/6/1
Y1 - 2018/6/1
N2 - We present optical and near-infrared observations of a low-luminosity (LL) Type IIP supernova (SN) 2016bkv from the initial rising phase to the plateau phase. Our observations show that the end of the plateau is extended to ≳140 days since the explosion, indicating that this SN takes one of the longest times to finish the plateau phase among Type IIP SNe (SNe IIP), including LL SNe IIP. The line velocities of various ions at the middle of the plateau phase are as low as 1000-1500 km s-1, which is the lowest even among LL SNe IIP. These measurements imply that the ejecta mass in SN 2016bkv is larger than that of the well-studied LL IIP SN 2003Z. In the early phase, SN 2016bkv shows a strong bump in the light curve. In addition, the optical spectra in this bump phase exhibit a blue continuum accompanied by a narrow Hα emission line. These features indicate an interaction between the SN ejecta and the circumstellar matter (CSM) as in SNe IIn. Assuming the ejecta-CSM interaction scenario, the mass loss rate is estimated to be yr-1 within a few years before the SN explosion. This is comparable to or even larger than the largest mass loss rate observed for the Galactic red supergiants (∼ 10-3M⊙yr-1 for VY CMa). We suggest that the progenitor star of SN 2016bkv experienced a violent mass loss just before the SN explosion.
AB - We present optical and near-infrared observations of a low-luminosity (LL) Type IIP supernova (SN) 2016bkv from the initial rising phase to the plateau phase. Our observations show that the end of the plateau is extended to ≳140 days since the explosion, indicating that this SN takes one of the longest times to finish the plateau phase among Type IIP SNe (SNe IIP), including LL SNe IIP. The line velocities of various ions at the middle of the plateau phase are as low as 1000-1500 km s-1, which is the lowest even among LL SNe IIP. These measurements imply that the ejecta mass in SN 2016bkv is larger than that of the well-studied LL IIP SN 2003Z. In the early phase, SN 2016bkv shows a strong bump in the light curve. In addition, the optical spectra in this bump phase exhibit a blue continuum accompanied by a narrow Hα emission line. These features indicate an interaction between the SN ejecta and the circumstellar matter (CSM) as in SNe IIn. Assuming the ejecta-CSM interaction scenario, the mass loss rate is estimated to be yr-1 within a few years before the SN explosion. This is comparable to or even larger than the largest mass loss rate observed for the Galactic red supergiants (∼ 10-3M⊙yr-1 for VY CMa). We suggest that the progenitor star of SN 2016bkv experienced a violent mass loss just before the SN explosion.
KW - supernovae: general
KW - supernovae: individual (SN2016bkv)
UR - http://www.scopus.com/inward/record.url?scp=85048339054&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85048339054&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aabee7
DO - 10.3847/1538-4357/aabee7
M3 - Article
AN - SCOPUS:85048339054
SN - 0004-637X
VL - 859
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 78
ER -