The calendar
Every night for eighteen months
Moonless astronomical dark is the number this observatory runs on: the sun more than 18° below the horizon and the moon below it at the same time. Sampled every five minutes for all 547 nights.
- Nights
- 547
- Total dark
- 4870 h
- Moonless dark
- 2474 h
- Mean per night
- 4.52 h
The shape of the year
Each bar is one night. The full height is astronomical dark; the solid part is the portion with the moon down. The monthly sawtooth is the lunar cycle, and the slow swell is midwinter — nights here run from about five hours of dark in December to ten and a half in July.
By month
September 2026
- Moonless dark
- 140 h
- Deep-sky nights
- 7
- Best night
- 08 · 9.67 h
October 2026
- Moonless dark
- 139 h
- Deep-sky nights
- 8
- Best night
- 08 · 8.92 h
November 2026
- Moonless dark
- 125 h
- Deep-sky nights
- 8
- Best night
- 06 · 8.08 h
December 2026
- Moonless dark
- 122 h
- Deep-sky nights
- 9
- Best night
- 06 · 7.5 h
January 2027
- Moonless dark
- 125 h
- Deep-sky nights
- 8
- Best night
- 09 · 7.58 h
February 2027
- Moonless dark
- 120 h
- Deep-sky nights
- 8
- Best night
- 07 · 8.25 h
March 2027
- Moonless dark
- 146 h
- Deep-sky nights
- 8
- Best night
- 10 · 9.08 h
April 2027
- Moonless dark
- 149 h
- Deep-sky nights
- 8
- Best night
- 08 · 9.83 h
May 2027
- Moonless dark
- 161 h
- Deep-sky nights
- 7
- Best night
- 04 · 10.33 h
June 2027
- Moonless dark
- 155 h
- Deep-sky nights
- 7
- Best night
- 02 · 10.58 h
July 2027
- Moonless dark
- 163 h
- Deep-sky nights
- 8
- Best night
- 02 · 10.67 h
August 2027
- Moonless dark
- 157 h
- Deep-sky nights
- 8
- Best night
- 01 · 10.33 h
September 2027
- Moonless dark
- 139 h
- Deep-sky nights
- 7
- Best night
- 01 · 9.83 h
October 2027
- Moonless dark
- 135 h
- Deep-sky nights
- 9
- Best night
- 01 · 8.5 h
November 2027
- Moonless dark
- 117 h
- Deep-sky nights
- 8
- Best night
- 26 · 7.67 h
December 2027
- Moonless dark
- 120 h
- Deep-sky nights
- 8
- Best night
- 28 · 7.42 h
January 2028
- Moonless dark
- 129 h
- Deep-sky nights
- 8
- Best night
- 25 · 7.92 h
February 2028
- Moonless dark
- 131 h
- Deep-sky nights
- 8
- Best night
- 24 · 8.75 h
The sky right now
00:00 at the observatory, astronomical dark. Moon below the horizon, 1% lit. 12 catalogued objects above ten degrees. Brightest is Arcturus, magnitude -0.04, 20 degrees up towards NW.
Up right now
Catalogued objects more than 10° above the horizon at 00:00, brightest first. Computed from the same figures the picture is drawn from.
| Object | Mag | Alt | Bearing |
|---|---|---|---|
| Arcturusα Boo · Bootes | -0.04 | 20° | 303° NW |
| Rigil Kentaurusα¹ Cen · Centaurus | -0.01 | 40° | 210° SW |
| Vegaα Lyr · Lyra | 0.03 | 26° | 8° N |
| Hadarβ Cen · Centaurus | 0.61 | 36° | 212° SW |
| Altairα Aql · Aquila | 0.77 | 47° | 42° NE |
| Antaresα Sco · Scorpius | 0.96 | 69° | 260° W |
| Spicaα Vir · Virgo | 0.98 | 23° | 268° W |
| Eta Carinae NebulaNGC 3372 · Emission nebula | 1.00 | 12° | 209° SW |
| Fomalhautα PsA · Piscis Austrinus | 1.16 | 25° | 113° SE |
| Mimosaβ Cru · Crux | 1.25 | 27° | 214° SW |
| Denebα Cyg · Cygnus | 1.25 | 11° | 27° NE |
| Acruxα¹ Cru · Crux | 1.33 | 25° | 210° SW |