Subaru Telescope Webcam – Stars Over the Mauna Kea Summit

The Subaru Telescope Webcam looks east from the Subaru Telescope across the summit of Mauna Kea on Hawaii Island, 4,139 meters (13,579 feet) above sea level. The twin domes of the W. M. Keck Observatory stand in the lower left of the frame, and smaller observatory domes sit along the ridge to the right. The rest of the picture is sky. After dark the low-light camera picks up a sky crowded with stars, meteors crossing the frame and, on some nights, the orange laser beams that summit telescopes shine into the sky. By day the domes stand white against a deep blue sky. A second tab carries the West view from the Canada-France-Hawaii Telescope (CFHT), which looks back across the summit toward Keck and Subaru.

About the Subaru Telescope

Subaru is the National Astronomical Observatory of Japan’s 8.2-meter (27-foot) optical and infrared telescope. It took its first scientific images in January 1999, and its single-piece primary mirror was the largest of its kind in the world until the Large Binocular Telescope opened in 2005. The building around it was shaped to cut down the air turbulence that blurs astronomical images. The telescope is named after the Pleiades, the star cluster that rises into this eastern sky on autumn evenings.

Its best-known instrument is Hyper Suprime-Cam, a 900-megapixel camera with a 1.5-degree field of view, used for surveys that map dark matter through weak gravitational lensing. Day-to-day support comes from the Hilo Base Facility in Hilo’s University Park, with a staff of about 100.

Subaru sits about 70 meters (230 feet) below the true top of Mauna Kea, which reaches 4,207 meters (13,803 feet). Measured from its base on the ocean floor, the mountain rises 9,330 meters (30,610 feet). It is a dormant volcano that last erupted between 4,500 and 6,000 years ago, and its summit now holds 13 observation facilities. In ancient Hawaii the summit was restricted to high-ranking ali’i and regarded as the region of the gods, and Maunakea, the spelling the University of Hawaii and the observatories use, remains a mountain of great cultural significance to Native Hawaiians.

The East view comes from a Sony FX3 with a 24 mm f/1.4 lens, run by Asahi Astro LIVE, the astronomy channel of the Japanese newspaper Asahi Shimbun, together with NAOJ. The West view camera sits at CFHT. From right to left it takes in the NASA Infrared Telescope Facility, Keck 2, Keck 1 and Subaru, with the small antennas of the Submillimeter Array and the James Clerk Maxwell Telescope lower left.

Weather and Climate on Mauna Kea

The summit has an alpine climate, and the long-term record from the observatory weather station at about 4,200 meters (13,800 feet) shows average lows below freezing in every month. Winter afternoons, from December to February, average about 6°C (42 to 43°F), with nights around -3°C (26 to 28°F). March and April are the coldest, with highs near 5°C (40 to 41°F), before May warms to about 9°C (48°F). Summer brings the mildest afternoons at around 10°C (49 to 51°F), with nights near -1°C (29 to 31°F). Autumn starts warm, with September averaging 10°C (51°F), then cools to about 7°C (44 to 45°F) in October and November.

The name Mauna Kea means white mountain, after its seasonally snow-capped summit. Snow can fall above 3,353 meters (11,000 feet) in any month, but it comes most often between October and April, so the camera can show snow around the domes after a winter storm and bare reddish cinder for much of the year.

Things to Do Near the Subaru Telescope

The summit is reached by the Maunakea Access Road, and the usual stopping point is the Onizuka Center for International Astronomy Visitor Information Station at 2,804 meters (9,200 feet). It runs free stargazing programs with its own telescopes, has short hiking routes and the First Light Store, and visitors are asked to acclimatize there before going higher. Above the station four-wheel drive is required and low range is advised on the steep road, while children under 13, pregnant women and people in poor health are advised to stay below.

Lake Waiau lies below the summit at 3,969 meters (13,022 feet), a small lake up to 3 meters (9.8 feet) deep when full. Down in Hilo, about 42 kilometers (26 miles) east of the summit, the ‘Imiloa Astronomy Center stands in University Park beside the base facilities of several Mauna Kea observatories, Subaru’s among them. The Hamakua Coast on the mountain’s northeastern side has Akaka Falls State Park, Wailuku River State Park and Kalopa State Recreation Area.

Similar Webcams You Might Like

Another observatory camera in Japan, and two more live views on Hawaii Island:

• Kiso Observatory Webcam
• Hilo Bay Webcam
• Kilauea Volcano Webcam

Frequently Asked Questions

What can you see on the Subaru Telescope Webcam?

The main camera faces east from the Subaru Telescope on the summit of Mauna Kea. The twin Keck domes sit in the lower left, smaller domes line the ridge to the right, and the rest of the frame is sky: stars and meteors at night, blue sky by day. The West view tab looks back at the Keck domes and Subaru from CFHT.

Where is the Subaru Telescope located?

On the summit of Mauna Kea on Hawaii Island, at 4,139 meters (13,579 feet), about 42 kilometers (26 miles) west of Hilo, where its base facility is.

Is there a live webcam on the Mauna Kea summit?

Yes. This page carries two from the summit, both run by Asahi Astro LIVE: the East view from the Subaru Telescope and the West view from the Canada-France-Hawaii Telescope.

Does this webcam show the Mauna Kea Visitor Center or Mauna Kea Beach?

No. Both cameras are at the summit, about 1,300 meters (4,400 feet) above the Visitor Information Station, and neither shows the station or any part of the coast.

Is there snow on Mauna Kea?

Not year-round. Snow can fall above 3,353 meters (11,000 feet) in any month, but it falls most often from October to April. After a winter storm the ground around the domes on camera can turn white.

What is the weather like on Mauna Kea?

Cold for Hawaii. At the summit, average highs run from about 5°C (40°F) in March to about 10°C (51°F) in July and September, and average lows stay below freezing all year.

What is the orange laser on the Subaru Telescope Webcam?

It is a laser guide star. Telescopes on the summit shine a laser into the sky to create an artificial star, which their adaptive optics use to correct for the blurring of the atmosphere, as the camera operator explains in the stream description.

Can you watch meteor showers live from Mauna Kea?

Yes. Asahi Astro LIVE bills both summit streams as meteor shower cams, and the stream descriptions link to a log of notable meteors caught on its cameras.

Source: Asahi Astro LIVE (credit: NAOJ, CFHT and Asahi Shimbun)