🌌 IC 4991
Object data
| Type | Galaxy |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 20h18m23.4s (304.5975°) |
| Declination | -41°03'01" (-41.0502°) |
| Magnitude | mag 11.54 |
| Apparent size | 2.91′ × 2.13′ |
| Other designations | IC 4991 |
A galaxy in Sagittarius.
Midnight transit date (best season to observe and image)
Location: Tokyo (change)
Around Jul 22, 2026
The date it transits around midnight (transit altitude about 13°)
This date has already passed this year. Next year (2027) it will be around Jul 23.
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
It never reaches 15° at this location (maximum altitude at transit: about 13°).
Night (sunset – sunrise)
Full darkness (dusk – dawn)
Moon up (darker = brighter moon)
Best time to observe (thick line)
Now
Sunset 17:11 → Dusk 18:36 → Dawn 4:19 → Sunrise 5:44