Detection of the gravitational lens magnifying a type Ia supernova.
Objects of known brightness, like type Ia supernovae (SNIa), can be used to measure distances. If a massive object warps spacetime to form multiple images of a background SNIa, a direct test of cosmic expansion is also possible. However, these lensing events must first be distinguished from other rare phenomena. Recently, a supernova was found to shine much brighter than normal for its distance, which resulted in a debate: Was it a new type of superluminous supernova or a normal SNIa magnified by a hidden gravitational lens? Here, we report that a spectrum obtained after the supernova faded away shows the presence of a foreground galaxy-the first found to strongly magnify a SNIa. We discuss how more lensed SNIa can be found than previously predicted.
Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583, Japan.
Robert M
RM
Quimby
Masamune
M
Oguri
Anupreeta
A
More
Surhud
S
More
Takashi J
TJ
Moriya
Marcus C
MC
Werner
Masayuki
M
Tanaka
Gaston
G
Folatelli
Melina C
MC
Bersten
Keiichi
K
Maeda
Ken'ichi
K
Nomoto