H-NGC869 — h Per
Open Cluster in Perseus
About
h Persei is the western half of Perseus's Double Cluster, lying near 7,460 light-years out and roughly 14 million years old. It is brighter than its partner at magnitude 5.3. Both clusters belong to the Perseus OB1 association, and this one is in the Herschel 400 list.
Imaging tips
- At 1,350–2,240 mm on APS-C (2,060–3,440 mm on full frame) one cluster fills a third to half of the frame; its twin NGC 884 lies about 27′ away, so go wider to catch both.
- Bright stars saturate easily: one imager kept subs to 30–60 s for the clusters to avoid overexposing them.
- Broadband is enough for the star colours; one imager added about 19–20 hours of 600 s Hα to pick up faint gas around the pair.
- Best around October and November; it peaks near 83° altitude from 50°N.
Facts
- Size
- 18′
- Magnitude
- 5.3
- Coordinates
- RA 2h 19.1m, Dec +57° 8′
- Framing, APS-C
- 1350–2240 mm
- Framing, full frame
- 2060–3440 mm
- Best months
- Oct, Nov
- Peak altitude
- 83° from 50°N, 68° from 35°N