Galaxy in Canes Venatici
Cat's Eye Galaxy (M94)
A bright inner ring of furious star formation surrounded by a much fainter outer disc, which for years led people to think it had two separate rings. It also appears to have very little dark matter, which for a spiral galaxy is genuinely strange and still unexplained.
The missing dark matter is the interesting part, and the claim is not a modest one: the rotation of the outer disc can be accounted for by the visible stars and gas alone, which almost no spiral manages. Either it formed in an unusual way or the measurement is being misread, and thirty years on nobody has closed the question.
- Catalogue
- M94
- Type
- Galaxy
- Constellation
- Canes Venatici
- Distance
- 16 million light-years
- Apparent magnitude
- 8.2
- Surface brightness
- 21.8 mag/□″
- Apparent size
- 11′ × 9′
- Right ascension
- 12h 51m
- Declination
- +41.12°
- Found by
- Pierre Méchain, 1781
Small enough that its 8.2 magnitudes arrive concentrated rather than smeared: 21.8 per square arcsecond, which is why it stands out from the sky better than its brightness alone suggests. Why surface brightness is the number that matters.
Could you see it?
Straightforward with 10×50 binoculars from Bortle 5.
| Sky | Eye | 10×50 | 80mm | 130mm | 200mm |
|---|---|---|---|---|---|
| Bortle 1 21.9 mag/□″ | No | Easy | Easy | Easy | Easy |
| Bortle 2 21.7 mag/□″ | No | Easy | Easy | Easy | Easy |
| Bortle 3 21.4 mag/□″ | No | Easy | Easy | Easy | Easy |
| Bortle 4 20.9 mag/□″ | No | Easy | Easy | Easy | Easy |
| Bortle 5 20.3 mag/□″ | No | Easy | Easy | Easy | Easy |
| Bortle 6 19.3 mag/□″ | No | Challenge | Challenge | Challenge | Challenge |
| Bortle 7 18.6 mag/□″ | No | No | No | No | No |
| Bortle 8 18.1 mag/□″ | No | No | No | No | No |
| Bortle 9 17.8 mag/□″ | No | No | No | No | No |
At the eyepiece
A very bright core inside a fainter halo — visually almost a comet. The inner ring that makes it interesting sits at the limit of what large amateur apertures show. Easy to find and quick to look at, which makes it a good first galaxy for anyone starting out.
When, and from where
Highest in the middle of the night in April. Well placed for the northern hemisphere and overhead for anyone near 41°N. South of 49°S it stays below the horizon.
| Latitude | Highest it gets | |
|---|---|---|
| 60°N Oslo, Anchorage | 71° | Never sets |
| 51°N London, Calgary | 80° | Never sets |
| 40°N New York, Madrid | 89° | |
| 30°N Cairo, Houston | 79° | |
| 0°N the equator | 49° | |
| 33°S Sydney, Cape Town | 16° | Low — in the murk |
Nearby in the sky
The whole catalogue →One more of the catalogue sits within five degrees, close enough to take in on the same night without moving far. Everything below is measured from M94 itself, not from the middle of Canes Venatici.
- M63 Sunflower Galaxy 4.7° apart Canes Venatici · magnitude 8.6 · binoculars from Bortle 5 or darker
- M106 Galaxy 8.4° apart Canes Venatici · magnitude 8.4 · binoculars from Bortle 4 or darker
- M51 Whirlpool Galaxy 9.3° apart Canes Venatici · magnitude 8.4 · binoculars from Bortle 5 or darker
- M109 Galaxy 15° apart Ursa Major · magnitude 9.8 · binoculars from Bortle 4 or darker
Terms on this page
- Dark matter Matter that has gravity but does not interact with light, and outweighs the visible sort five to one.
- Spiral, elliptical and irregular The three basic shapes galaxies come in, and roughly what they mean.
One of 110. Positions J2000; the sky is the final authority.