M106 — NGC 4258
Galaxy in Canes Venatici
About
A spiral galaxy in Canes Venatici, about 24 million light-years away. Its water maser, a natural microwave beacon in the gas disk, gave the first direct distance to a galaxy and now anchors the cosmic distance ladder. Two extra arms show up in X-rays but not in visible light.
Imaging tips
- Large enough to span a third to half of the frame at 1,280–2,130 mm on APS-C, or 1,950–3,260 mm on full frame.
- Faint for its size at 22.5 mag/arcsec², and a galaxy needs broadband filters. Amateur results on one gallery page range from about 1 hour of 1-minute subs to 3.4 hours of 5-minute subs.
- The edge-on spiral NGC 4217 sits at the edge of wider frames, along with NGC 4220 and other small galaxies, so a shorter focal length adds company.
- One imager used a CLS-CCD light-pollution filter with 2-minute subs for 2 hours; best around March and April.
Facts
- Size
- 19′ × 8′
- Magnitude
- 8.4
- Coordinates
- RA 12h 19.0m, Dec +47° 18′
- Framing, APS-C
- 1280–2130 mm
- Framing, full frame
- 1950–3260 mm
- Best months
- Mar, Apr
- Peak altitude
- 87° from 50°N, 78° from 35°N