H-NGC3115 — Spindle
Galaxy in Sextans
About
A lenticular galaxy in Sextans about 32 million light-years away, seen almost exactly edge-on. William Herschel found it in 1787, and it was once classed as an elliptical. Its central black hole is estimated at one to two billion solar masses, among the most massive nearby. It is in the Herschel 400 list.
Imaging tips
- Spans only about 8×3′, so it needs a long focal length: 3030–5050 mm on APS-C.
- At about 21 mag/arcsec² the disk is modest in brightness; one Bortle 8 image still used 24 × 240 s with a light-pollution filter.
- Broadband imaging suits a galaxy; little gas or dust remains, so narrowband adds nothing here.
- Best around February and March; it peaks near 32° from 50°N.
Facts
- Size
- 8′ × 3′
- Magnitude
- 9.2
- Coordinates
- RA 10h 5.2m, Dec −7° 43′
- Framing, APS-C
- 3030–5050 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Feb, Mar
- Peak altitude
- 32° from 50°N, 47° from 35°N