H-NGC7640
Galaxy in Andromeda
About
A small barred spiral in Andromeda, tilted close to edge-on, which makes its bar and dust lanes easier to pick out than its arms. Sources put it anywhere from about 18 to 30 million light-years away. It may have had an encounter with another galaxy fairly recently.
Imaging tips
- Only about 11×2′, so it needs a long focal length: 2200–3670 mm on APS-C, or 3380–5630 mm on full frame.
- Faint for its size at 23.3 mag/arcsec², so plan many hours of broadband data. One imager gathered 7 h 20 min of LRGB in 5-minute subs.
- One imager's image, taken at 0.4″ per pixel with a 3,912 mm scope, shows the bar, the dust lanes and blue star clusters.
- Best around August and September, when it passes close to overhead (about 81° from 50°N).
Facts
- Size
- 11′ × 2′
- Magnitude
- 11.3
- Coordinates
- RA 23h 22.1m, Dec +40° 51′
- Framing, APS-C
- 2200–3670 mm
- Framing, full frame
- 3380–5630 mm
- Best months
- Aug, Sep
- Peak altitude
- 81° from 50°N, 84° from 35°N