M48 — Herschel's Cluster
Open Cluster in Hydra
About
An open cluster in Hydra about 2,500 light-years away and several hundred million years old, with at least 438 known members. Messier recorded it with a declination about five degrees off, so the position in his list is empty sky.
Imaging tips
- About 54′ across: 450–750 mm on APS-C frames it with space around it.
- A small refractor with a one-shot colour camera gave a usable image from 24 × 2 min (48 minutes); another team suggests 3–5 minute subs for this cluster.
- Sparse and faint overall at 23.1 mag/arcsec². A 7.5-hour RGB project found no nebulosity, so more hours add stars, not gas.
- Satellite trails crossed that 7.5-hour data repeatedly, and sigma clipping did not remove all of them.
- Best in January and February.
Facts
- Size
- 54′
- Magnitude
- 5.8
- Coordinates
- RA 8h 13.8m, Dec −5° 48′
- Framing, APS-C
- 450–750 mm
- Framing, full frame
- 690–1150 mm
- Best months
- Jan, Feb
- Peak altitude
- 34° from 50°N, 49° from 35°N