# T Coronae Borealis (Blaze Star)

T Coronae Borealis (Blaze Star) is a star in the constellation Corona Borealis, magnitude 10.2.

**The Blaze Star: a sleeping recurrent nova that astronomers expect to flare to naked-eye brightness.**

In May 1866 the Irish astronomer John Birmingham spotted a new 2nd-magnitude star in the Northern Crown. It was an unremarkable 10th-magnitude star caught in a nova outburst — and in February 1946 it did it again. That second eruption was found independently by three observers, one of them a 15-year-old schoolboy from Wales, Michael Woodman. The name Blaze Star has been used since 1866, and the IAU made it official in 2025.

T Coronae Borealis is a pair: a red giant and a white dwarf circling each other every 228 days. Gas from the giant piles up on the white dwarf until it ignites in a runaway nuclear explosion, and the system brightens about 3,000-fold. Two eruptions 80 years apart make it a recurrent nova, a rare kind of [variable star](https://astropilot.space/glossary/variable-star), and suggested it flares on roughly that schedule.

In 2015 it began a sustained brightening like one seen in 1938, eight years before its last eruption, and a dip in 2023 resembled one just before 1946. Predictions of an imminent outburst have come and gone; as of October 2026 the Blaze Star is still waiting.

T Coronae Borealis (Blaze Star) is 3,000 light-years away: the light we see from it set off around 980 BC, 200 years before the first recorded Olympic Games were held.

## Did you know?

- **Seen in 1217?.** Old records hint that T Coronae Borealis may also have been seen in 1217 and 1787, long before anyone knew what a recurrent nova was.
- **Birmingham’s other star.** John Birmingham, who caught the 1866 eruption, also gave La Superba in Canes Venatici its name, in 1876.

Normally a 10th-magnitude star needing binoculars or a small telescope, about a degree south-east of Epsilon Coronae Borealis on the crown’s eastern side. Learn the field now: when it erupts it will briefly rival Alphecca, the crown’s brightest star.

## When and where to see it

It is best placed in the evening sky around June, when it crosses the meridian at about 10 pm local time (around midnight in May). It can be seen from everywhere north of 64°S and never sets north of 64°N.

At its highest it stands 66° up from 50°N, 81° up from 35°N, 64° up from the equator, 29° up from 35°S.

## Facts

- Type: Star
- Constellation: Corona Borealis
- Designations: Blaze Star, T CrB, HR 5958, HD 143454, HIP 78322
- Magnitude: 10.2
- Position: RA 15h 59.5m, Dec +25° 55′ (J2000)
- Spectral type: M3IIIe_sh
- Colour: orange (B−V 1.27)
- Brightness: varies from magnitude 2 to 10.8
- Distance: 3,000 light-years
- Discovered: John Birmingham, 1866, Discovered in outburst; seen earlier as an unremarkable 10th-magnitude star

Open AstroPilot to see when T Coronae Borealis (Blaze Star) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view. https://astropilot.space/object/t-coronae-borealis