H-NGC4151 — Eye of Sauron
Galaxy in Canes Venatici
About
A spiral galaxy in Canes Venatici, about 52 million light-years away, whose centre holds a black hole that is still growing. Carl Seyfert's 1943 paper, which defined the Seyfert class, described six galaxies, and this was among them. The nickname Eye of Sauron comes from its look.
Imaging tips
- About 6′ by 5′, so it is too small to frame: use a long focal length and a fine pixel scale.
- Faint at 23 mag/arcsec². One imager used about 30 hours of LRGB on a 32-inch telescope; another took 101 six-minute subs, roughly 10 hours.
- A brighter blue ring sits close to the centre while the outer arms are faint, so the arms are what the long integrations are for.
- Best in March and April; it peaks near 79° from 50°N.
Facts
- Size
- 6′ × 5′
- Magnitude
- 10.7
- Coordinates
- RA 12h 10.6m, Dec +39° 24′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Mar, Apr
- Peak altitude
- 79° from 50°N, 86° from 35°N