-24.6272° · -70.4042° · 2,480 m
We sell darkness
by the hour.
A working observatory on the Meseta de Ilaró, 74 km from the nearest town and 11 km of that on graded dirt. Five instruments, a Bortle 1 sky, and a booking calendar that tells you the truth about the moon.
- Median SQM
- 21.9
- Best night
- 10.67 h
- Instruments
- 5
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.
- Sun
- -79°
- Moon
- 1% down
- Up now
- 12
The moon closes us 71 nights out of 547.
Deep-sky work needs two things at once: the sun more than 18° below the horizon, and the moon below it altogether. Most observatory websites quote the first number and quietly omit the second.
We publish both, for every night in the next eighteen months, computed rather than estimated. Deep Field is genuinely unbookable on about 22 nights a month. On those nights we run Moonlight instead — a 610 mm mirror on the lunar terminator is worth more than an apology.
- Nights in the published calendar547
- Usable for deep-sky work142
- No moonless dark at all71
Six ways to spend a night
All sessions- Any moonFirst DarkThree hours, small group, the southern sky explained from nothing.3 h · 8 places$85
- Moon under 15%Deep FieldFive hours on Vaciado, moonless nights only, galaxies and globulars.5 h · 5 places$165
- Moon under 30%The Long ExposureA full imaging night on Sombra, from calibration frames to a reduced result.7 h · 3 places$320
- Moon over 55%MoonlightBright nights used properly: lunar terminator, planets, narrowband.4 h · 8 places$95
- Any moonSun at HydrogenNinety minutes on Solano in the afternoon. Prominences, filaments, active regions.2 h · 10 places$40
- Moon under 10%Winter ResidencyFive consecutive nights around new moon, one project, all five instruments.5 nights · 4 places$2400
Five instruments, and what each is honestly for
Aperture is not the only number that matters, and the largest telescope here is the wrong one for about half of what people come to see.
Every instrument in detail- Vaciado
- 610 mm · f/4.1 · 2014
- Faint galaxies and galaxy groups · Globular clusters resolved to the core · Planetary nebulae with a narrowband filter
From the log
The observing journal2027-02-02
The one week a year the sky is useless
High-altitude dust from the north for six consecutive nights. Transparency 1, SQM down to 20.4 at the zenith with no moon — a full magnitude and a hal…
Sofía Marchant · seeing 2/5 · SQM 20.4
2027-01-17
A three-millimagnitude dip, eventually
Transit photometry run on Sombra: five hours of continuous 30-second exposures either side of a predicted ingress, defocused deliberately so the star …
Wren Okonkwo · seeing 3/5 · SQM 21.62
2026-11-28
Nine hours on the Tarantula, and the flats that nearly ruined it
Nine hours of hydrogen-alpha on NGC 2070 through Sombra, in 600-second subs. Guiding held at about 0.6 arcseconds RMS all night, which is the mount be…
Bo Lindqvist · seeing 3/5 · SQM 21.8
