Globular cluster in Lepus
M79
A globular sitting in the winter sky, where globulars have no business being: they crowd around the galactic centre, which is a summer object. It is almost certainly an immigrant, though opinion on where from keeps moving — the Canis Major dwarf was the favourite for years, and the current suspects are the wreckage of two much older galaxies the Milky Way swallowed.
The wider point is that the halo of our galaxy is largely other galaxies' remains, and telling which is which is done by chemistry and orbit rather than by looking. M79 is around forty-one thousand light-years away, sits well below the plane, and would be unremarkable if it were anywhere it belonged.
- Catalogue
- M79
- Type
- Globular cluster
- Constellation
- Lepus
- Distance
- 41,000 light-years
- Apparent magnitude
- 7.7
- Surface brightness
- 21.1 mag/□″
- Apparent size
- 9′
- Right ascension
- 5h 24m
- Declination
- −24.55°
- Found by
- Pierre Méchain, 1780
Small enough that its 7.7 magnitudes arrive concentrated rather than smeared: 21.1 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 the naked eye from Bortle 1 or darker; with 10×50 binoculars from Bortle 5.
| Sky | Eye | 10×50 | 80mm | 130mm | 200mm |
|---|---|---|---|---|---|
| Bortle 1 21.9 mag/□″ | Easy | 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 | Challenge | Challenge | Challenge | Challenge |
| Bortle 8 18.1 mag/□″ | No | No | No | No | No |
| Bortle 9 17.8 mag/□″ | No | No | No | No | No |
At the eyepiece
A small, moderately bright ball in a season and a part of the sky where nothing like it belongs. At 200mm the outer edges begin to grain. The oddity of finding a globular in the winter sky is the reason to visit, more than anything the eyepiece will give you.
When, and from where
Highest in the middle of the night in December. Overhead at 25°S and southerly enough to sit low from northern Europe, though never out of reach there — only north of 65°N does it stop rising at all.
| Latitude | Highest it gets | |
|---|---|---|
| 60°N Oslo, Anchorage | 5° | Low — in the murk |
| 51°N London, Calgary | 14° | Low — in the murk |
| 40°N New York, Madrid | 25° | |
| 30°N Cairo, Houston | 35° | |
| 0°N the equator | 65° | |
| 33°S Sydney, Cape Town | 82° |
Nearby in the sky
The whole catalogue →Nothing else in the catalogue is especially close; the nearest is 19° apart, which is a separate trip rather than a nudge of the tube. Everything below is measured from M79 itself, not from the middle of Lepus.
- M41 Open cluster 19° apart Canis Major · magnitude 4.5 · binoculars from Bortle 9 or darker
- M42 Orion Nebula 19° apart Orion · magnitude 4.0 · binoculars from Bortle 3 or darker
- M43 De Mairan's Nebula 19° apart Orion · magnitude 9.0 · needs more than binoculars
- M78 Nebula 25° apart Orion · magnitude 8.3 · binoculars from Bortle 4 or darker
One of 110. Positions J2000; the sky is the final authority.