T Coronae Borealis (T CrB), informally nicknamed the Blaze Star, is a recurring nova

Nova

A nova is a cataclysmic nuclear explosion in a star caused by the accretion of hydrogen on to the surface of a white dwarf star, which ignites and starts nuclear fusion in a runaway manner...

 in the constellation

Constellation

In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 Corona Borealis

Corona Borealis

Corona Borealis is a small constellation in the northern sky. Its name is Latin for "northern crown", a name inspired by its shape; its main stars form a semicircular arc. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and remains one of the 88 modern...

. It normally has a magnitude

Apparent magnitude

The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...

 of about 10, which is near the limit of typical binoculars. It has been seen to outburst twice, reaching magnitude 2.0 on May 12, 1866 and magnitude 3.0 on February 9, 1946. Though a more recent paper shows the 1866 outburst with a possible peak range of magnitude 2.5 ± 0.5. Even when outbursting at magnitude 2.5, this recurrent nova is dimmer than about 120 stars in the night sky.

Further reading

• R and T Coronae Borealis: Two Stellar Opposites at Sky & Telescope

External links

• http://www.daviddarling.info/encyclopedia/B/Blaze_Star.html
• AAVSO: Quick Look View of AAVSO Observations (get recent magnitude estimates for T CrB)