H-NGC7209
Open Cluster in Lacerta
About
A loose open cluster in Lacerta, about 3,810 light-years away and roughly 420 million years old. One member, SS Lacertae, is a binary whose brightness stopped varying in the mid-20th century, which is put down to a third star. It is in the Herschel 400.
Imaging tips
- Sources give 14–25′ across, so it is a wide-field target: 970–1620 mm on APS-C, or 1490–2480 mm on full frame.
- A few stars between 7th and 9th magnitude stand out in a sparse cluster, over a faint 22.3 mag/arcsec² field; broadband colour suits a cluster, and the stars look bluish.
- One imager built an LRGB frame from 30 minutes in each channel at 1.17″ per pixel.
- Best around August and September; it passes almost overhead, peaking near 86° from 50°N.
Facts
- Size
- 25′
- Magnitude
- 6.7
- Coordinates
- RA 22h 4.9m, Dec +46° 30′
- Framing, APS-C
- 970–1620 mm
- Framing, full frame
- 1490–2480 mm
- Best months
- Aug, Sep
- Peak altitude
- 87° from 50°N, 79° from 35°N