Bode's Galaxy
What is Bode's Galaxy?
Galaxies· Distance ~12 million ly. The finest spiral of the northern sky — a 'grand-design' galaxy with two smooth, perfectly wound arms, sharing the eyepiece with its gravitationally entangled neighbour, the Cigar Galaxy M82. Johann Bode found it in 1774, hence the name.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Bode's Galaxy is in your sky right now: https://nowsky.org/solar/sky?sel=m81 — location and time set automatically, no login.
Distance and scale
| Distance | ~12 million ly |
|---|---|
| Diameter | ~90,000 ly |
| Central black hole | ~70 million Suns |
| Constellation | Ursa Major |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- How far is Bode's Galaxy from Earth?
- ~12 million ly.
- How big is Bode's Galaxy?
- ~90,000 ly.
- In one line, what is Bode's Galaxy?
- Galaxies — The finest spiral of the northern sky — a 'grand-design' galaxy with two smooth, perfectly wound arms, sharing the eyepiece with its gravitationally entangled neighbour, the Cigar Galaxy M82.
- Where is Bode's Galaxy in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
SN 1993J, the supernova found by a Spanish amateur
On 28 March 1993 the Spanish amateur astronomer Francisco García discovered a supernova in M81. At 12 million light-years it was among the brightest supernovae seen from the northern hemisphere in the late twentieth century, reaching about 10th magnitude and visible in small telescopes. The star at that position had been photographed beforehand from the ground, and it proved to be a red supergiant of some fifteen solar masses that exploded after a companion had stripped most of its envelope.
Its spectrum changed within weeks from a hydrogen-rich Type II to a hydrogen-poor Type Ib, establishing the intermediate class "Type IIb". In radio waves the ring of debris ploughing into the surrounding material has been tracked for more than thirty years, a rare near-real-time record of a supernova remnant growing. In 2004 the companion star was detected in ultraviolet light.
The galaxy in depth
Bode's Galaxy, M81, is a spiral about 12 million light-years away in Ursa Major and one of the brightest galaxies in the sky. Around 90,000 light-years across — much like the Milky Way — it shows two thick, smooth arms wound in near-perfect symmetry, the archetype of a grand-design spiral. A black hole of some 70 million solar masses lies at its centre; star birth thrives in the arms while the core is dominated by old stars.
Johann Bode discovered it in 1774 and Messier catalogued it as number 81 in 1779. It anchors the M81 Group of about three dozen galaxies, and a close encounter a few hundred million years ago left it linked to the Cigar Galaxy M82 and NGC 3077 by streams of hydrogen — the same encounter that likely ignited M82's starburst. In 1993 Supernova 1993J flared here, one of the brightest of the twentieth century.
From Dubhe in the Dipper's bowl, move a hand-span north-west and you reach M81 and M82, about a full-moon width apart. Select M81 in the Sky view to mark it; in reality binoculars show both galaxies in one field, which is why this pair is the first galaxy target recommended to beginners.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.