Call for Proposals 18A

The East Asian Observatory is happy to invite PI observing proposals for semester 18A at JCMT. Proposal submission is via the JCMT proposal handling system, Hedwig. For full details, and for proposal submission please see

The 18A Call for Proposals closes on the 15th of September, 2017.

If this is your first time using Hedwig, you should ‘Log in’ and generate an account. There is a Hedwig ‘Help’ facility at the upper right corner of each page, and individual Help tags in many other places.

Please contact us at if you have remaining questions.

Green Land Telescope Receiver testing progressing well at the JCMT

The Greenland Telescope (GLT) is a novel project; taking a 12-meter radio antenna – prototype for the Atacama Large Millimeter/Submillimeter Array (ALMA) project from Chile, and relocating this telescope to Greenland.

By repurposing this telescope astronomers can take advantage of the near-ideal conditions of the Arctic to study the Universe at specific radio frequencies. Whilst the telescope is being commissioned the initial receiver that will be used at the GLT is being tested at the JCMT in Hawaii. Last week the alignment of the instrument was performed this morning using the Sun as a source – and at the JCMT the first astronomical source for this instrument!

form more information visit: and

The GLT receiver installed inside the receiver cabin on the JCMT.

The inside of the GLT receiver

Delivery of the GLT receiver to JCMT

– 20170814

EAO Mid Term Review Committee meet in Hilo

The EAO Mid Term Review committee are meeting this week in Hilo to discuss the future of the JCMT. When the East Asian Observatory took over operation of the JCMT back in 2015 it was for an initial 5 years. Since that time we have had 5 semesters of great science. We have successfully completed three large programs (S2COSMOS, SCOPE, MALATANG). We have uncovered new star-forming events in the sub-mm. We have discovered stellar mass black holes. Our EAO regions have gained access to both Subaru and SMA. Recently we welcomed Vietnam as an observing partner in the JCMT. So much to celebrate!

– 20170727

EACOA Fellow, Tie Liu, welcomed to EAO Hilo

EACOA Fellow Dr Tie Liu is the first EACOA Fellow to come to work at the EAO office in Hilo, Hawaii from KASI.

Tie Liu’s main research interest is high-mass star formation and molecular clouds. Tie is the head of a large consortium undertaking the SCOPE, SCUBA-2 Continuum Observations of Pre-protostellar Evolution, program studying Planck cold clumps at JCMT. This program is now (as of July 2017) complete after 300 hours of SCUBA-2 time over the past year and a half.

Tie is now turning the focus of this study to follow-up observations with JCMT (e.g. POL-2) as well as many other telescopes (e.g., ALMA, SMA, NRO 45-m, KVN, FAST 500m …).

The Staff at EAO are pleased to welcome Tie Liu into the scientific division and hope many more astronomers decide to visit JCMT in the future as long term visitors, to engage directly with JCMT staff.

– 20170724


Astronomers from the East Asian Observatory/JCMT are in Taipei, Taiwan this week for the Asia Pacific Meeting of the International Astronomical Union (APRIM). If you are there please pop by our booth and say hello!

Maunakea Wonders – Teacher workshop success

For two days at the end of June EAO/JCMT hosted its first “Maunakea Wonders Teacher Workshop” primarily aimed at newly qualified teachers here on the island of Hawai’i. One day was spent learning about the cultural, environmental and astronomical role Maunakea plays combined with a trip to visit the CFHT (Canada France Hawai’i Telescope), and the JCMT. The second day was spent in the classroom discovering what Hawaii more about astronomy on the big island and the resources available to the community, teachers and students in Hawaii.

The workshop was kindly supported by MKAOC/CFHT and the University of Hawai’i Hilo’s School of Education.

First day of the Maunakea Wonders Teacher workshop included a trip to the Canada France Hawaii Telescope and then to JCMT.

Discovering cosmic distances

Discovering Teaching opportunities in Hawaii – with Gemini’s Starlab.

– 20170703

AstroDay 2017

EAO/JCMT staff once again volunteered their time to spend the day connecting with the community at the annual Hilo AstroDay. This year we explored the concept of magnetism and polarization in space.

For more about AstroDay please see:

A summary of the cryogenic work on SCUBA-2 this past winter

SCUBA-2 has been back on the sky for the past month producing excellent data, following both planned engineering down time to work on the instrument cryogenics and unplanned – to fix a vacuum leak.

The end of 2016 was a busy time for the EAO ETIS (Engineering, Technical Information Systems) staff. From the middle of the 2016 we were aware of a change in performance of one of the (two) pulse tube coolers (PTC) that cools the SCUBA-2 inner radiation shields and internal mirrors to below 4K. We were able to continue to use SCUBA-2 without any impact on the quality of the data, while we planned the major task of taking the 3 tonne instrument off the antenna and replacing both of the instrument PTC cold heads with new remote motor models.

The dilution fridge mixture was removed and the warm-up started on October 5th. SCUBA-2 was back on the sky with new PTCs and was operational by November 18th, 1 week ahead of schedule. However, during the subsequent cooldown, the cryostat vacuum was found not to be as good as expected.

Later in December, when we temporarily warmed-up (to 4K) to replace a small pump in the dilution refrigerator (DR) gas handling system – a regular procedure, the poor vacuum became a serious issue. Additional problems with pumps in the GHS and too high a pressure in the DR still prevented cooling below 1K. This is well above the operating temperature of the TES detectors.

The only course was to warm the instrument to ambient temperature and to then carry out extensive leak checking of the cryostat. A leak was found that we could fix. However, on detailed inspection, we discovered that the O-ring between the feedthrough and the top plate of the DR insert was cracked and would fail soon if we did not replace it.

Two weeks of skill and persistence was required to replace this O-ring to enable SCUBA-2 to be yet-again pumped, leak checked and cooled prior to the end of January. With the vacuum leak fixed, the cause of the second issue with the GHS that prevented cooling below 1K became apparent. This issue was caused by a particle filter on the input of the pump. After removing the offending filter SCUBA-2 was operational by February 5th.

The loss of an additional 6 weeks of observing with SCUBA-2 impacted our users. However, by catching the failing O-ring before a total loss of vacuum, we avoided the potential for more serious consequences to the instrument and a bigger disruption of the observing schedule. An extended period of good stable weather in recent weeks has allowed some of the affected programs to makeup for the missed nights.

In addition to the cryogenic work, new improved thermal blocking filters have been installed between the instrument window and the band defining filters for the detector arrays. We are now investigating the change in optical power on the detector arrays, to see if this has modified the stray light environment within the 4K box and improved SCUBA-2’s performance.

Jamie Cookson works on the repair of SCUBA-2.

– 20170407

Blue skies for Venus observations

Over the past two weekends the JCMT has been open and observing during the day. These daytime observations are needed to observe the middle atmosphere (altitude 70-110 km) of Venus.

The aim is to better understand atmospheric physics and chemistry. The way to advance understanding of fundamental atmospheric physics and chemistry in general is to study the atmospheres of individual planets – specifically in this case Venus!

The JCMT is used for this study because sub-millimeter spectroscopy is uniquely powerful for investigations of this altitude range on Venus. JCMT’s location on Maunakea, its ability to safely point arbitrarily close to the sun, and its observation flexibility (capability to modify observing strategies in as little as 5 minutes, during the observations) make it uniquely well-suited to Venus research.

Here is a video of the sky above the EAO office in Hilo – can you spot Venus? If you want to see what the weather is like on Maunakea click here. For a link to the EAO Hilo office weather click here.