🌌 M102 (Spindle Galaxy)
Object data
| Type | Galaxy |
|---|---|
| Constellation | Draco |
| Right ascension | 15h06m29.5s (226.6230°) |
| Declination | +55°45'48" (+55.7633°) |
| Magnitude | mag 9.9 |
| Apparent size | 4.7′ × 1.9′ |
| Other designations | NGC 5866 |
A galaxy in Draco. Whether Messier's record was a duplicate observation of M101 has long been debated; today it is most often identified with the lenticular galaxy NGC 5866, though some historical ambiguity remains.
Midnight transit date (best season to observe and image)
Location: Tokyo (change)
The date it transits around midnight (transit altitude about 70°)
This date has already passed this year. Next year (2027) it will be around May 5.
For about 2–3 weeks either side of this date, the object stays high from evening to dawn — its observing season.
Best time to observe tonight
Tonight (Oct 11 evening – Oct 12 dawn) · Location: Tokyo (full darkness = end of astronomical dusk to start of dawn, altitude ≥ 15°)
Moon tonight: New moon (age 29.2 days, 0% illuminated) — Little moonlight — a good time for faint objects
Hours of full darkness (end of astronomical dusk to start of dawn) when it is above 15° — the darkest sky, mostly clear of buildings and trees.
Sunset 17:11 → Dusk 18:36 → Dawn 4:19 → Sunrise 5:44