Open cluster
M38 (M38)
In Auriga (Aur) • Magnitude 7.4 • 21 arcminutes
Open the free AstroPlanner with M38 pre-selected, scored against your telescope, location, and the live cloud forecast.
A loose open cluster in Auriga with a cross-shaped pattern among its brightest stars, and the oldest of the three Auriga Messier clusters at about 220 million years. Just 30 arcminutes away sits NGC 1907, a smaller, older cluster thought to have formed from the same giant gas cloud long ago.
M38 at a glance
| Catalog IDs | M38, N 1912 |
| Type | Open cluster |
| Constellation | Auriga (Aur) |
| Right ascension | 05h 28m 41s |
| Declination | +35° 51' 00" |
| Apparent magnitude | 7.40 |
| Angular size | 21.0 × 21.0 arcmin |
| Max altitude at 45°N | 81° |
| Best imaging months | Sep, Oct, Nov |
How to image M38
M38 sits in the constellation Auriga at right ascension 05h 28m 41s and declination +35° 51' 00". To frame and integrate it well, AstroPlanner will compute the optimal moonless window for tonight from your location, the field-of-view fit against your sensor and focal length, the suggested total integration time given your aperture and sky Bortle class, and a cloud-aware schedule that drops it from the plan if your nearest cloud forecast spike overlaps the best altitude window.