A type Ia supernova discovered Wednesday, August 24, in the nearby galaxy M101 in Ursa Major is the nearest type Ia supernova astronomers have found since 1986. The brightness of this exploding star is on the rise, and it could be visible in a 6-inch telescope within a week or so.
Palomar Transient Factory
Astronomers at the Palomar Transient Factory project on California’s Palomar Mountain discovered the supernova using the Oschin Schmidt telescope at Palomar Mountain Observatory. The supernova is designated SN 2011fe and lies 58.6 arcseconds west and 270.7 arcseconds south of the center of M101, which lies some 21 million light-years away. The supernova’s equinox 2000.0 coordinates are 14h03m, 54°16'25". At discovery, the supernova glowed feebly at magnitude 17.2 but is brightening rapidly, reaching magnitude 13.8 on Thursday. The star may reach 11th magnitude or better at its peak. M101 itself is a beautiful object, a face-on “pinwheel” type spiral with fairly low surface brightness arms, but a stunning form. Visibility of the galaxy and its supernova will be best in the evening sky over the next few days, before the Big Dipper sinks too far and before early September brings the Moon into the equation.
Type Ia supernovae are catastrophic explosions that result from binary stars consisting of a white dwarf star and a companion, in which the dwarf draws material from its companion until reaching a critical point, reigniting nuclear fusion and causing a runaway explosion of the white dwarf that typically outshines the entire host galaxy for some time.
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