Galaxy in Virgo
M90
A large spiral in the process of dying: the cluster has taken most of its gas, star formation has all but stopped, and the arms are smoothing away. It is blueshifted too, so it is dying in our direction.
Blueshifted galaxies are rare enough to be worth counting — a handful in the whole sky — and they are all in Virgo, all falling inward faster than the expansion carries them away. M90 has left a long trail of its own gas behind it, and what is left is enough for perhaps a few hundred million more years of star formation.
- Catalogue
- M90
- Type
- Galaxy
- Constellation
- Virgo
- Distance
- 58 million light-years
- Apparent magnitude
- 9.5
- Surface brightness
- 22.0 mag/□″
- Apparent size
- 9′ × 4′
- Right ascension
- 12h 37m
- Declination
- +13.17°
- Found by
- Charles Messier, 1781
Small enough that its 9.5 magnitudes arrive concentrated rather than smeared: 22.0 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 4.
| 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 | Challenge | Challenge | Challenge | Challenge |
| Bortle 6 19.3 mag/□″ | No | No | 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
Large, elongated and reasonably bright, with a strong core — one of the better shaped galaxies in Virgo for a modest telescope. That it is quietly dying is invisible; what you see is a healthy-looking spiral that has already stopped making new stars.
When, and from where
Highest in the middle of the night in March. Passes overhead at 13°N and rises from everywhere except the far south — below 77°S it never clears the horizon.
| Latitude | Highest it gets | |
|---|---|---|
| 60°N Oslo, Anchorage | 43° | |
| 51°N London, Calgary | 52° | |
| 40°N New York, Madrid | 63° | |
| 30°N Cairo, Houston | 73° | |
| 0°N the equator | 77° | |
| 33°S Sydney, Cape Town | 44° |
Nearby in the sky
The whole catalogue →This is a busy patch. 4 more of the catalogue sit within five degrees, which is a binocular field or two — worth planning a session around rather than visiting once. Everything below is measured from M90 itself, not from the middle of Virgo.
- M89 Galaxy 40′ apart Virgo · magnitude 9.8 · binoculars from Bortle 4 or darker
- M58 Galaxy 1.4° apart Virgo · magnitude 9.7 · binoculars from Bortle 4 or darker
- M91 Galaxy 1.4° apart Coma Berenices · magnitude 10.2 · binoculars from Bortle 3 or darker
- M87 Virgo A 1.7° apart Virgo · magnitude 8.6 · binoculars from Bortle 5 or darker
One of 110. Positions J2000; the sky is the final authority.