C24 — Perseus A Cluster
Galaxy in Perseus
About
NGC 1275, nicknamed Perseus A, sits at the centre of the Perseus Cluster, some 225–230 million light-years away. Its active black hole powers a web of delicate gas filaments around the galaxy, and these are the main prize for imagers.
Imaging tips
- Only about 2′ across, so it is too small to frame: use a long focal length and a fine pixel scale.
- Faint at 22.1 mag/arcsec², so plan many hours of data.
- The gas filaments are the hard part and stand out most in Hα. One imager gathered about 67 hours, 100 ten-minute subs of them in Hα, and a narrowband APOD shows filaments up to 20,000 light-years long.
- Best around October and November; it peaks near 82° altitude from 50°N.
Facts
- Size
- 2.2′ × 1.5′
- Magnitude
- 12.2
- Coordinates
- RA 3h 19.8m, Dec +41° 31′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Oct, Nov
- Peak altitude
- 82° from 50°N, 84° from 35°N