Cr13
Open Cluster in Cassiopeia
About
An old open cluster in Cassiopeia holding roughly 150 stars, found by William Herschel in 1787. Distance estimates differ: about 4,100 light-years in one study and 7,200 in another. Its age of about 1.8 billion years is said to give it a faded look.
Imaging tips
- About 7′ across (Wikipedia); at 2,020–3,370 mm on APS-C (3,090–5,160 mm full frame) it fills a good part of the frame.
- Dust in this part of Cassiopeia leaves a faint grey haze over the background stars.
- Two dark nebulae, LDN 1325 and LDN 1326, lie off to one side of the cluster, so a wider frame can take them in.
- A published example used 4 hours of LRGB broadband data (6 × 10 minutes per channel).
- Best in September and October; it peaks near 77° altitude from 50°N.
Facts
- Size
- 8′
- Magnitude
- 8.0
- Coordinates
- RA 1h 29.5m, Dec +63° 18′
- Framing, APS-C
- 3030–5050 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Sep, Oct
- Peak altitude
- 77° from 50°N, 62° from 35°N