Open AccessSupernova 1994aj: a probe for pre‐supernova evolution and mass‐loss from the progenitor
Author(s) -
Benetti S.,
Cappellaro E.,
Danziger I. J.,
Turatto M.,
Patat F.,
Della Valle M.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01198.x
Subject(s) - physics , astrophysics , ejecta , supernova , balmer series , photometry (optics) , astronomy , luminosity , light curve , radius , emission spectrum , absolute magnitude , spectral line , galaxy , stars , computer security , computer science
Extensive photometric and spectroscopic observations of SN 1994aj until 540 d after maximum light have been obtained. The photometry around maximum suggests that the SN belongs to the Type II Linear class, with a peak absolute magnitude of M V ∼−17.8 (assuming H 0 =75 km s −1 Mpc −1 ). The spectra of SN 1994aj were unusual, with the presence of a narrow line with a P Cygni profile on top of the broad Balmer line emission. This narrow feature is attributed to the presence of a dense superwind surrounding the SN. At 100–120 d after maximum light the SN ejecta start to interact with this circumstellar material. The SN luminosity decline rates slowed down [γ R =0.46 mag (100 d) −1 ], becoming less steep than the average late luminosity decline of normal SN II [∼1 mag (100 d) −1 ]. This dense ( ˙M / u W ∼10 15 g cm −1 ) wind was confined to a short distance from the progenitor ( R out =∼5×10 16 cm), and results from a very strong mass‐loss episode ( ˙M =10 −3 M⊙ yr −1 ), which terminated shortly before explosion (∼5–10 yr).