Announcements

8 August 2017: Project News We’ve just received confirmation that the LSST Town Hall at AAS 231 will take place on Wednesday, January 10th, 2018 at 7:30 pm. Given LSST’s increasing focus on commissioning and operations planning, this Town Hall will focus on developments in the planning of LSST’s observing strategy and commissioning policies. Representation from the LSST Corporation and Science Collaborations will also briefly highlight key, ongoing initiatives to help the community prepare for science with LSST. The countdown to LSST 2017 continues! Don’t forget to review the most recent agenda when making your plans; if you have questions, please ask them on Slack channel #lsst2017 or on the LSST Community forum. An Ash Dome was safely lifted and installed on the Auxiliary Telescope on Cerro Pachón on August 3. Details about this exciting development can be found in this week’s blog post. The successful installation of a Camera Data Acquisition System …

3 August 2017: New results from the Dark Energy Survey confirm that the Universe is mostly made of dark energy (70%) and dark matter (26%), with normal baryonic matter comprising just a smidge (4%). In other words, the Universe is mostly made of stuff we don’t understand! The results of the survey, which is being carried out with DECam on the CTIO Blanco telescope, were derived from high precision maps of gravitational lensing and large scale structure.

2 August 2017: Gemini confirms a new class of variable stars called Blue Large-Amplitude Pulsators. They are significantly bluer than main sequence stars of the same luminosity demonstrating that they are relatively hot. The new pulsating stars vary with periods ranging from 20 to 40 minutes and amplitudes spanning 0.2 – 0.4 magnitude. These characteristics have not been observed in any known hot pulsators. Astronomers using the Multi-Object Spectrograph (GMOS) on the Gemini South telescope have confirmed a new class of variable stars called Blue Large-Amplitude Pulsators (BLAPs). Pawel Pietrukowicz (Warsaw University Observatory, Poland) led the study as part of the Optical Gravitational Lensing Experiment (OGLE), a variability sky survey conducted on the 1.3-meter Warsaw Telescope at Las Campanas Observatory, Chile. Following up on the team’s discovery of 14 candidate stars the team used GMOS to obtain spectra for three of the candidates. The Gemini data confirmed these stars have helium-rich atmospheres and …

25 July 2017: Project News LSST 2017 is fast approaching! More than 240 participants have registered for the August 14-18 meeting, and the detailed agenda has been posted. Changes are still being made, so check back before the meeting to see the most up-to-date version. LSST Data Management Subsystem Scientist Mario Juric gave a presentation titled What to Expect of the LSST Archive: The LSST Science Platform at the LSST Science Collaboration Chairs/Project Science Team meeting on July 18th. Slides from his talk are available here. Dr. Amanda Bauer, Head of Education and Public Outreach, presented LSST Education and Public Outreach at the same meeting; her slides can be viewed here. The azimuth structure of the Telescope Mount Assembly (TMA), which is supported on a set of six azimuth and six radial hydrostatic bearings, floated on oil for the first time this month at subcontractor Asturfeito’s facility in Spain. The system was pressurized …

21 July 2017: Ten billion years ago, a massive star ended its life in a brilliant explosion three times as bright as all of the stars in our galaxy, the Milky Way, combined. News of its death, which recently reached Earth, was detected in the Dark Energy Survey being carried out with DECam at the CTIO Blanco telescope (pictured, above right). The supernova is one of the most distant ever discovered and confirmed.

20 July 2017: Spectroscopy using the Gemini Multi-Object Spectrograph on the Gemini South telescope in Chile verifies the extreme distance of one of the most distant superluminous supernovae ever studied. The following text is reproduced from the University of California Santa Cruz press release issued on July 21, 2017. The paper is available here. At a distance of 10 billion light years, a supernova detected by the Dark Energy Survey team is one of the most distant ever discovered and confirmed. SANTA CRUZ, CA--The death of a massive star in a distant galaxy 10 billion years ago created a rare superluminous supernova that astronomers say is one of the most distant ever discovered. The brilliant explosion, more than three times as bright as the 100 billion stars of our Milky Way galaxy combined, occurred about 3.5 billion years after the big bang at a period known as "cosmic high noon," when the rate …

11 July 2017: Project News The registration and hotel booking deadline for the LSST 2017 Project and Community Workshop is July 20--less than two weeks away--so please make your arrangements as soon as possible. Watch the LSST 2017 website for the detailed agenda, scheduled to be released in mid-July. An LSST management team visited vendors Asturfeito and Tekniker in Spain from June 19-23 to inspect progress and review upcoming work. The group attended a multi-day testing and verification workshop for the Telescope Mount Assembly (TMA) at Asturfeito, and the Camera cable wrap assembly and the Primary/Tertiary Mirror (M1M3) cover at Tekniker. Photos from the visit are available in the LSST Gallery. The Factory Assembly Plan (FAP) Review for the LSST Coating Plant took place from July 5-7 at the Von Ardenne GmnH facility in Dresden, Germany. Members of LSST’s Telescope & Site (T&S) team reviewed the Coating Plant assembly process described in the …

27 June 2017: A team of Korean astronomers uses imaging from the Gemini Multi-Object Spectrograph (GMOS) on Gemini North to characterize the rotation of active asteroid P/2010 A2’s largest fragment. The observations show that this faint and tiny (about the size of an American football field) asteroid, which underwent a mass ejection episode, is slowly rotating, indicative of an impact fragmentation rather a rotational breakup. In January 2017, the active and fragmented main belt asteroid P/2010 A2 (hereafter A2) made its closest approach to the Earth after its 2010 discovery, when it exhibited a mysterious comet-like dust trail. Prior to this year’s passage, the fragments had not yet been characterized, due to the extremely small size (~120 meters in diameter) and faintness of this object. A Korean team, led by Yoonyoung Kim of Seoul National University, received time on Gemini North to observe the object’s 2017 close passage when the fragments and associated …

20 June 2017: Project News Don’t forget to register for the LSST 2017 Project and Community Workshop, which will take place at the Westin La Paloma in Tucson, AZ the week of August 14-18. Although the deadline to suggest a session has passed, we encourage ongoing discussions on the LSST2017 Community Forum. Your ideas and feedback will be valuable as sessions are planned and the Workshop agenda is finalized. Make LSST 2017 YOUR meeting! The LSST Science Advisory Committee will have a face-to-face meeting the morning of August 14, in coordination with LSST 2017. All attendees to LSST 2017 are welcome to join. Please refer to the published LSST 2017 agenda for the time and location of the meeting. The LSST Operations Proposal Review meeting took place on June 7-8. This in-person meeting between Red Team reviewers and project leadership enabled productive discussion that will contribute to the overall strengthening of the Proposal. …

19 June 2017: Discovered with DECam on the CTIO Blanco telescope, the diminutive moon S/2017 J1, only a mile across, takes 2 years to complete an orbit around Jupiter. Its retrograde orbit — in the direction opposite to Jupiter’s spin — tells us that the moon originated elsewhere and was captured by Jupiter. The inset shows the discovery images taken by astronomers Scott Sheppard and Chad Trujillo. The discovery brings to 69 the total number of Jovian moons known.

6 June 2017: The first exoplanet discovered using the Gemini Planet Imager (GPI) is a young, cool object between 2–10 Jupiter masses. Identified as 51 Eridani b, new research indicates that its color is redder than similar brown dwarfs and might be due to clouds in its atmosphere. The research also hints that the formation of this exoplanet is likely due to the collapse of icy disk materials followed by the accretion of a thick gas atmosphere – much like the process astronomers think probably formed the gas giants in our Solar System. An international team of astronomers led by Abhijith Rajan (School of Earth and Space Exploration, Arizona State University) observed the exoplanet 51 Eri b using GPI spectroscopy and determined that the planet is redder than similar brown dwarfs seen elsewhere. "This might be due to presence of clouds, similar to young L-type planetary mass companions," said Rajan. "A possible reason …

6 June 2017: Project News Registration is now open for the LSST 2017 Project and Community Workshop, which will take place at the Westin La Paloma in Tucson, AZ the week of August 14th. Click here for more details and a link to registration. Agenda topics are currently being solicited; you can make your suggestions by clicking “Suggest a Session” on the workshop home page. We look forward to seeing you at #LSST2017! A draft of the LSST Operations Proposal is now in the hands of 19 external red team reviewers. The review team’s reading period has ended, and feedback will be discussed with Project leadership at a face-to-face meeting on June 7-8. A joint teleconference between the Project Science Team and the chairs of Science Collaborations was held on May 30. The main topic was “LSST Plans for Cadence Optimization.” Slides are available at this link, and the audio recording it can …

24 May 2017: Project News Mark your calendars for the LSST 2017 Project and Community Workshop, which will take place the week of August 14th in Tucson, AZ. The workshop agenda will include Project topics, suggestions from the Community, and unstructured time for you to set up your own meetings. Registration will open by next week. We look forward to seeing you at #LSST2017! Highlights of footage taken by the multimedia team that visited Cerro Pachón in March have been edited into a short video that shows the current status of construction at the telescope site. The video was distributed widely throughout the project, posted on LSST’s public website, and posted to social media. Two major winter storms swept through Cerro Pachón last week, leaving behind some road damage, more than 20 inches (51 cm) of snow, and a (manageable) impact on the construction schedule. More information and pictures here. The Project Science …

11 May 2017: Researchers combine images from Gemini South’s wide-field adaptive optics system (GeMS/GSAOI) with data from the Hubble Space Telescope (HST) to determine the proper motion of a distant cluster of stars. The observations, the first to use ground-based adaptive optics to precisely measure the motion of a cluster at such a large distance, allowed astronomers to set a lower limit for the mass of our Milky Way while providing clues about the cluster’s origin. A study of the proper motion (apparent motion in the sky due to an object's motion around our galaxy) of several substructures across the Milky Way’s halo is underway at Gemini South. As part of this study the team used Adaptive Optics (AO) at Gemini South, along with data from HST, to focus on a distant cluster called Pyxis. The work allowed the team to set a lower limit for the Milky Way’s mass of 950 million …

28 April 2017: Dear Reader, we anticipate settling into a bi-weekly distribution for the LSST Digest once we have a full-time Communications Manager. Thank you for your continued interest. Project News The LSST Project Office is currently supporting an on-site incurred cost audit from the NSF. This is the first time LSST and AURA have taken part in this type of audit. Going forward, we expect it will become routine. The audit will investigate LSST’s compliance with the financial requirements of our Cooperative Agreement as well as Office of Management and Budget’s Uniform Guidance. A multimedia team visited Cerro Pachón in early April to gather high-quality images and video footage of LSST's construction progress. LSST staff assisted the team in obtaining material safely and without disrupting construction progress. Images and more information found here. LSST's EPO staff has signed a contract to purchase Webdam, a system for Digital Asset Management. Webdam will provide …

19 April 2017: Located 92 AU from the Sun, DeeDee is the second most distant trans-Neptunian object known — only the dwarf planet Eris is further away. Discovered in the Dark Energy Survey, which is being carried out at CTIO, DeeDee is petite, with a diameter ¼ that of Pluto. DeeDee was discovered by an international team, including NOAO astronomers Alistair Walker and Tim Abbott.

4 April 2017: Project News A team from LSST traveled to Germany for the Coating Plant Final Design Review on March 20th-24th. In Dresden, the team inspected the coating chamber to ensure all the appropriate program requirements will be met. They then traveled to Deggendorf to inspect the progress of the vacuum vessels. More information and images can be seen here. LSST leadership will be in Washington, DC, April 3 – 7, for a two-day meeting of the AURA Management Council for LSST (AMCL). This oversight body meets three times a year to discuss technical progress and review its fiduciary responsibilities for the LSST construction project. Priority topics this time include the Data Management replan and Operations planning. While in DC, S. Kahn, B. Willman, and V. Krabbendam will visit the congressional appropriations committee staff, the Office of Management and Budget, and participate in the LSSTC meeting (see below). The LSST Systems Engineering …

24 March 2017: Project News Several members of the LSST team are visiting the Von Ardenne GmbH facility in Dresden, Germany, this week for a Final Design Review of the Coating Plant. Meanwhile, on Cerro Pachón in Chile, our web cam shows the progress being made on the summit facility with the extensive steel structure of the main building evident and the floor structures inside the dome also extending about the ring wall. Multiple cranes have been working simultaneously on the lower enclosure in preparation for the arrival of the Dome system vendor. The camera team at SLAC and BNL has now accepted delivery of enough science-grade sensors to complete three rafts. Fabrication of the second raft is beginning. Each raft holds 9 sensors; a total of 189 sensors on 21 rafts are required to complete the LSST camera focal plane. Also, the cryostat grid that holds the rafts in place has been …

23 March 2017: Using the Gemini Planet Imager (GPI), a team of astronomers led by J. Chilcote (University of Toronto) found that the low mass stellar companion β Pictoris b is about 13 times more massive than Jupiter with a surface temperature of about 1720 K. While these parameters are in good agreement with earlier observations, they allow better comparisons with planetary evolution models. The Gemini data indicate that β Pictoris b best matches an exoplanet with an atmosphere like that of a low-surface gravity (L21) brown dwarf. Observations at the Gemini South telescope in Chile, using the Gemini Planet Imager (GPI), are refining our understanding of the β Pictoris system. The system contains the ~ 13 Jupiter mass companion β Pictoris b which is at the mass boundary sometimes used to distinguish between an exoplanet and a brown dwarf. Brown dwarfs are objects that are not massive enough for sustained nuclear reactions. …

22 March 2017: While observing for the DECam Legacy Survey (DECaLS), Rongpu Zhou (University of Pittsburgh) set up a camera to capture a time-lapse of the evening. For the first 18 seconds of the video, the moon illuminates the foreground as if it were daylight, while the night sky rotates overhead. As the moon sets, many more stars become visible, and our galaxy, the Milky Way, rises as the Magellanic Clouds set behind the Blanco 4m Telescope. The time-lapse was taken on 4 March 2017.Click the image to view the time-lapse and to see more options.