H-NGC659
Open Cluster in Cassiopeia
About
This Cassiopeia open cluster, nicknamed Yin-Yang, lies about 8,200 light-years away and is estimated at 20 million years old. Caroline Herschel found it in 1783. It sits right beside the larger NGC 663 and is in the Herschel 400 list.
Imaging tips
- At about 5–6′ it is too small to frame alone: use a long focal length and a fine pixel scale, or go wide for a group portrait.
- NGC 654 is about 1.2° away (approximate), so a wide field is needed to hold the two together; with NGC 663 and IC 166, one image shows four clusters.
- In one RGB frame on a 120 mm refractor with a 0.7× reducer, NGC 663 sat at the bottom, NGC 654 at left and NGC 659 at right.
- Surface brightness is 20.0 mag/arcsec², so it is not a faint target.
- Best in October and November; it peaks near 79° from 50°N.
Facts
- Size
- 5′
- Magnitude
- 7.9
- Coordinates
- RA 1h 44.5m, Dec +60° 41′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Oct, Nov
- Peak altitude
- 79° from 50°N, 64° from 35°N