H-NGC1245
Open Cluster in Perseus
About
NGC 1245 is an old, rich open cluster in Perseus, roughly 9,400–10,400 light-years away depending on the source. Its 10′ apparent size works out to about 27 light-years across. William Herschel found it in 1786, and it is also listed as Collinder 38.
Imaging tips
- At 2420–4040 mm on APS-C (3710–6190 mm full frame) the 10′ cluster takes up a third to half of the frame, with no catalogued neighbours of note.
- One imager's 2008 LRGB frame used 30 minutes of luminance (10 × 3 min) and 30 minutes per colour (5 × 6 min) on a 160 mm f/7.5 refractor.
- That same frame also picked up faint background galaxies, the brightest of them PGC 12019 at magnitude 15.7.
- Another imager shot it at 0.94″ per binned pixel with 60-second unguided subs in R, G and B, covering 16.8′ across the frame.
- At 22 mag/arcsec² it sits at the edge of what counts as faint. Best in October and November, when it passes near 87° altitude from 50°N.
Facts
- Size
- 10′
- Magnitude
- 8.4
- Coordinates
- RA 3h 14.8m, Dec +47° 14′
- Framing, APS-C
- 2420–4040 mm
- Framing, full frame
- 3710–6190 mm
- Best months
- Oct, Nov
- Peak altitude
- 87° from 50°N, 78° from 35°N