The Moon and the stars — September 2027

Lunar occultations of stars to magnitude 9.5, computed for your location

Every night the Moon slides in front of stars. A star doesn't fade behind it — it switches off, then switches back on at the other edge, often an hour later. Pick your place and what you observe with; the list keeps what you can realistically see.

Naked eye Binoculars Small telescope (80 mm) Telescope (200 mm)

23 occultations you can see from New Delhi with small telescope (80 mm) this month, on 13 nights · 1147 in all from there

Mon

Tue

Wed

Thu

Fri

Sat

Sun

2 7

1 13

1 19

3 24

2 25

3 26

1 27

Times in IST. A night runs from noon to noon, so an event at 01:30 stays with the evening before. On each Moon, the numbered marks show where on the limb each star disappears or reappears.

Night of Mon 6 Sep

1
19:07:34 TYC 6781-1134-1 V 7.2
Disappears at the dark limb
28° up in the SSW · dusk · PA 59° · cusp 44°
2
20:41:56 HIP 77197 V 7.7
Disappears at the dark limb
15° up in the SW · dark sky · PA 63° · cusp 49°

Night of Tue 7 Sep

1
21:31:25 HIP 81821 V 7.9
Disappears at the dark limb
14° up in the SW · dark sky · PA 46° · cusp 38°
2
22:15:25 HR 6216 V 6.7
Disappears at the dark limb
7° up in the SW · dark sky · PA 119° · cusp 68°

Night of Fri 10 Sep

1
21:37:50 χ1 Sgr V 4.9
Disappears at the dark limb · reappears 23:05:44 at the bright limb
34° up in the SSW · dark sky · PA 67° · cusp 77°
2
21:51:06 HIP 95486 V 7.3
Disappears at the dark limb
33° up in the SSW · dark sky · PA 49° · cusp 59°

Night of Sun 12 Sep

1
19:48:21 HIP 103703 V 6.1
Disappears at the dark limb
34° up in the SE · dark sky · PA 62° · cusp 79°

Night of Mon 13 Sep

1
19:22:54 HIP 107412 V 6.7
Disappears at the dark limb
27° up in the SE · dark sky · PA 11° · cusp 29°

Night of Sat 18 Sep

1
23:14:53 101 Psc V 6.2
Reappears at the dark limb
48° up in the E · dark sky · PA 204° · cusp 52°

Night of Sun 19 Sep

1
02:01:31 26 Ari V 6.1
Reappears at the dark limb
74° up in the ESE · dark sky · PA 213° · cusp 56°

Night of Tue 21 Sep

1
00:06:40 χ Tau V 5.4
Disappears at the bright limb · reappears 00:56:00 at the dark limb
29° up in the ENE · dark sky · PA 112° · cusp 57°
2
00:09:54 HIP 20258 V 7.8
Reappears at the dark limb
30° up in the ENE · dark sky · PA 290° · cusp 59°
3
02:02:32 HIP 20626 V 7.8
Reappears at the dark limb
54° up in the E · dark sky · PA 182° · cusp 13°

Night of Thu 23 Sep

1
03:23:51 HIP 31031 V 8.3
Reappears at the dark limb
46° up in the E · dark sky · PA 261° · cusp 77°
2
03:48:11 TYC 1883-919-1 V 8.2
Reappears at the dark limb
51° up in the E · dark sky · PA 342° · cusp 22°
3
04:34:31 TYC 1883-2108-1 V 8.4
Reappears at the dark limb
61° up in the E · dark sky · PA 256° · cusp 72°

Night of Fri 24 Sep

1
04:10:35 HIP 36864 V 8.1
Reappears at the dark limb
42° up in the E · dark sky · PA 206° · cusp 16°
2
04:42:56 HIP 36898 V 7.3
Reappears at the dark limb
49° up in the E · dark sky · PA 246° · cusp 56°

Night of Sat 25 Sep

1
02:47:22 HIP 41765 V 7.4
Reappears at the dark limb
11° up in the ENE · dark sky · PA 231° · cusp 36°
2
03:09:15 HIP 41833 V 6.5
Reappears at the dark limb
16° up in the ENE · dark sky · PA 247° · cusp 52°
3
03:48:53 TYC 1395-948-1 V 8.3
Reappears at the dark limb
24° up in the E · dark sky · PA 268° · cusp 73°

Night of Sun 26 Sep

1
04:07:19 HIP 46650 V 7.7
Reappears at the dark limb
14° up in the E · dark sky · PA 258° · cusp 61°

Night of Mon 27 Sep

1
05:06:54 HIP 51195 V 7.9
Reappears at the dark limb
13° up in the E · dark sky · PA 295° · cusp 82°

Reading the list

The Moons are drawn from LRO LOLA topography (a 40 KB relief map), lit by the Sun as it is at that moment and turned to the Moon's real libration: north up, east to the left. A dark-limb event — the star vanishing into, or popping out of, the unlit edge of the Moon — is easy to see. At the bright limb only bright stars show against the glare. PA is where on the limb it happens, measured from north through east; the cusp angle is the distance from the nearest horn of the crescent. graze marks a star passing within 3″ of the edge from your place: a few kilometres from a graze line, where it may blink several times behind mountains.

Instrument	dark limb	bright limb
Naked eye	V ≤ 3.0	V ≤ 1.0
Binoculars	V ≤ 6.5	V ≤ 3.5
Small telescope (80 mm)	V ≤ 8.5	V ≤ 5.5
Telescope (200 mm)	V ≤ 9.5	V ≤ 7.0

Those limits are rules of thumb: the dark-limb limit drops by 2.5 magnitudes × (lit fraction − 0.4) in moonglare and by 1 in twilight; events with the Moon under 5° are left out, and daylight events except for the brightest stars. Stars are from Gaia DR3 to G 9.5, with Hipparcos-2 for the brightest and the Yale Bright Star Catalogue for names; the Moon is from the JPL DE431 ephemeris. Times are for the Moon's mean limb, ±2 s — mountains at the edge can move a contact by a few seconds, and much more near a graze.