William O'Brien Observatory.

Research observatory · Marine on St. Croix, Minnesota

William O'Brien Observatory

William O'Brien Observatory is a research observatory in Marine on St. Croix, Minnesota.

William O'Brien Observatory in brief

Open to the public
No regular public access
Bortle class
Not yet rated

Official site

Can you visit William O'Brien Observatory? No regular public access

No public access; UMN public Friday Night Observing is on campus.

For telescope views near William O'Brien Observatory, see the observatories open to the public and astronomy clubs nearby; clubs hold free public star parties.

William O'Brien Observatory
William O'Brien Observatory

What William O'Brien Observatory observes

The list does not describe the instruments at William O'Brien Observatory yet; the official site has them.

How dark the sky is at William O'Brien Observatory

William O'Brien Observatory has no Bortle rating in the list yet. The scale below shows what each class looks like.

1 mag 8.0 21.99+ 2 mag 7.5 21.89+ 3 mag 7.0 21.69+ 4 mag 6.5 20.49+ 5 mag 6.0 19.50+ 6 mag 5.5 18.94+ 7 mag 5.0 18.38+ 8 mag 4.5 18.00+ 9 mag 4.0
The Bortle scale. Each panel shows the class number, the faintest star the naked eye reaches at the zenith, and the darkest-edge sky brightness reading of that class in mag/arcsec².

Sky brightness and class come from the World Atlas of Artificial Night Sky Brightness (Falchi et al. 2016, CC BY-NC 4.0), with natural skyglow added, at the coordinates below. Research telescopes are often sited on mountains above the haze, so the real sky can be darker than the map suggests.

William O'Brien Observatory among the observatories of Minnesota

Baylor Regional Park Big Bog State Recreation Area Boundary Waters Canoe Area Wilderness Cascade River State Park Garden Island State Recreation Area George Crosby Manitou State Park Hayes Lake State Park Itasca State Park Judge C.R. Magney State Park La Salle Lake State Recreation Area Northwest Angle Old Mill State Park Savanna Portage State Park Scenic State Park Split Rock Lighthouse State Park Temperance River State Park Voyageurs National Park Zippel Bay State Park Chippewa National Forest Superior National Forest Joseph J. Casby Observatory Cherry Grove Observatory Eisenhower Observatory Macalester College Observatory Eagle Lake Observatory (Onan Observatory) Paul P. Feder Observatory Goodsell Observatory Sola Fide Observatory William O'Brien Observatory Marine on St. Croix, Minnesota William O'Brien Observatory Marine on St. Croix, Minnesota
Dark sky place Research or private observatory Observatory open to the public

Green dots are observatories open to the public, blue dots research or private sites, squares dark sky places; select one for its page. See Minnesota observatories for the full list.

The coordinates on this page point to zip 55047 (approximate): 45.199°N, 92.826°W.

Map data © OpenStreetMap contributors. Open the larger map · Directions. Mountain observatory roads are often gated after dark; go only on a scheduled public night.

Dark sky places, observatories and clubs near William O'Brien Observatory

Nearest dark sky places

PlaceWhereBortleDistance
Baylor Regional ParkMinnesota498 km (61 mi)
Chippewa Moraine State Recreation AreaWisconsin3113 km (70 mi)
Beaver Creek ReserveWisconsin4129 km (80 mi)
Chequamegon-Nicolet National ForestWisconsin2183 km (114 mi)
Savanna Portage State ParkMinnesota2184 km (114 mi)
Copper Falls State ParkWisconsin3214 km (133 mi)

Other observatories open to the public within 150 km

  • Macalester College ObservatorySt. Paul, Minnesota, 40 km (25 mi). Occasional free open observatory nights listed on the Macalester calendar
  • Eisenhower ObservatoryHopkins, Minnesota, 55 km (34 mi). Hopkins Community Education public viewing nights (register via Community Ed), fall and winter-spring sessions
  • Goodsell ObservatoryNorthfield, Minnesota, 87 km (54 mi). Free monthly Friday open houses, about 7-9 pm, with historic and modern telescopes; check site for weather cancellations
  • Eagle Lake Observatory (Onan Observatory)Norwood-Young America, Minnesota, 98 km (61 mi). Minnesota Astronomical Society public star parties at Eagle Lake Observatory (see mnastro.org calendar)
  • Hobbs ObservatoryFall Creek, Wisconsin, 130 km (81 mi). Public observing Saturdays May-Oct when clear, from 30-45 min after sunset for about two hours (none during Northwoods Starfest); CVAS volunteers

Astronomy clubs within 150 km

Star parties near William O'Brien Observatory

Star partyNearDistanceUsual timing
Bootleg Fall Star PartyHarmon, Illinois477 km (297 mi)Autumn new moon
Bootleg Spring Star PartyHarmon, Illinois477 km (297 mi)Spring new moon
Great Lakes Star GazeGladwin, Michigan674 km (419 mi)September new moon
Nebraska Star PartyValentine, Nebraska704 km (437 mi)Summer new moon

Planning a trip? Astrotourism in Minnesota puts the dark sky places, observatories, clubs, star parties, planetariums and science centers of the state on one map, with the best night out worked out.

William O'Brien Observatory record

Every value in the observatories dataset for William O'Brien Observatory
ID353
NameWilliam O'Brien Observatory
Address621 Nason Hill Rd N
CityMarine on St. Croix
StateMN
Zip55047
CountryUSA
Webhttps://cse.umn.edu/mifa/research/obrien
Publicn
Lat45.19880
Lon-92.82580
LatLonSpotzip 55047 (approximate)
StatusActive
StatusNoteUniversity of Minnesota 30-inch optical/IR research telescope
PublicNoteNo public access; UMN public Friday Night Observing is on campus
Sourceshttps://cse.umn.edu/mifa/research/obrien

From the site's observatories dataset (observatories_q426). Distances are computed from the coordinates.