Introduction

Finally, the Research Corporation for Science Advancement has announced that it will be holding one of its Scialog series of workshops on Early Science with the LSST. These events are targetted at early career faculty, where early career is here defined as “spanning the time from the first year on the faculty through recently post-tenure”. The series will see ~50 selected Fellows interact with ~10 senior scientists with the goal of mitigating “two impediments to realizing the full scientific potential of LSST: the lack of seed funding to ignite early LSST discoveries with these data, and the critical need to create the cross-disciplinary connections required to tackle the biggest questions LSST is poised to address”.

In other news, the latest iteration of the Astronet Science Vision and Roadmap has been published, covering the period 2022-2035. Astronet is a consortium of astronomy funding agencies and associated bodies (e.g. ESO, ESA) from across Europe and its objective is to provide a strategic framework for planning coordinated investment in European astronomy. This latest update has been delayed by Covid-19, and features a series of reports by thematic panels, which feed a roadmap for the coming decade or so. As such, this represents a significant document, summarising the aspirations of the community, but with, inevitably, a focus on those projects funded at a Europe-wide level - e.g. through ESO, ESA, or included in the European Strategy Forum on Research Infrastructures (ESFRI). Equally inevitably, this leaves LSST in a somewhat anomalous position, since it will clearly play a major role in the next decade of European astronomy, but European involvement in LSST is being organised through a number of national and institutional in-kind contributions, rather than under the aegis of a Europe-wide entity. To try to address that anomaly, Stephen Smartt and I organised a letter to Astronet, signed by the leaders of almost all the European in-kind contributions attesting to the importance of LSST for their communities in the coming decade, and encouraged our Science Collaboration Points of Contact to provide input to the various thematic reports. Reassuringly LSST is well represented in many of those, but it remains outside the coordinated framework. That repeats what happened with the previous iteration of the roadmap, which included, as one of its primary recommendations, the development of a wide-field spectroscopic facility on an 8-10m telescope, motivated largely by the requirements of LSST follow-up. It seems a missed opportunity for Astronet that one of the key science drivers for European astronomy remains outside its framework just because the substantial European involvement is funded by Astronet members acting individually, rather than together.

Those with ideas for future newsletter items should contact the LSST:UK Project Managers (George Beckett and Terry Sloanlusc_pm@mlist.is.ed.ac.uk), while everyone is encouraged to subscribe to the Rubin Observatory Digest for more general news from the US observatory team.

Bob Mann

LSST:UK Communications Officer

Bob Mann

Lasair’s role in uncovering the most energetic transient ever, AT2021lwx

A team led by Philip Wiseman at the University of Southampton has uncovered what is being dubbed the “largest cosmic explosion ever witnessed”, named AT2021lwx. This remarkable explosion occurred nearly 8 billion light-years away and was initially detected by the Zwicky Transient Facility (ZTF). Its luminosity exceeds that of any known supernova by tenfold, and despite its vast distance has been visible for over three years. The light curve is single-peaked and shows a 150-day rise followed by very slow, steady decline. The event has been widely covered in the world’s media, both online as well as on the radio and television news bulletins.

The team first became interested in the event in 2021 as a possible superluminous supernova due to its long rise-time, and it was observed by the ePESSTO+ collaboration after being ingested into their classification queue from the Lasair broker. However, the first ePESSTO+ spectrum was inconclusive and the transient was archived. In 2022, AT2021lwx reappeared during a Lasair query for orphan transients – those with no apparent host galaxy – and the 2021 spectrum was subsequently re-examined. Upon close inspection, absorption lines at z=1 were present, which placed the absolute magnitude at M~-26 and made AT2021lwx one of the most luminous transients ever observed.

There is no clear explanation behind the cause of the event. The extreme luminosity likely requires the presence of a supermassive black hole of around 100 million solar masses. The UK-led work favours a giant gas cloud being accreted by a dormant supermassive black hole, while a US-centered team favour the tidal disruption of a star fifteen times the mass of the Sun. Follow-up observations are ongoing in an aim to distinguish between these scenarios, while the search is on in archival data to find similar historical events. LSST is the prime survey to discover similar objects in the future and the Lasair broker will be the centre of the search for such extreme events.

LSST:UK session at NAM2023

Bob Mann and Stephen Smartt

Team meeting in London

Recent LSST:UK Science Centre outputs

The LSST:UK Science Centre has recently produced the following technical reports.

Terry Sloan

Forthcoming meetings of interest

There is a busy schedule of potentially interesting meetings in the coming months. Registration is now open for the National Astronomy Meeting, in Cardiff, during 3rd--7th July (http://nam2023.org ) at which LSST:UK will run three sessions (see above). The website for the Rubin Project and Community Workshop 2023 is now available, with options to suggest sessions and to contribute a poster or talk abstract. Earlier in the Summer, Rubin Data Delegates might be interested to join the DP0 Virtual Summer School (online, 12th–16th June).

Other meetings of potential interest for the coming months include:

• 12th-14th June: LSST Galaxies Collaboration meeting, Paris

• 20th–22nd June: The Transient and Variable Universe, held at University of Urbana Champaign, Illinois, USA

• 3rd-7th July: The National Astronomy Meeting 2023, held in Cardiff, with a three-part session on “UK involvement in the Vera C. Rubin Observatory: Legacy Survey of Space and Time”

• 24th–28th July: DESC Collaboration Meeting (SLAC), California, USA

• 24th–28th July: ZTF Summer School, University of Minnesota/ virtual

Members of the Consortium (not in receipt of travel funding through one of the Science Centre grants) may apply for travel support for meetings of this kind via the the LSST:UK Pool Travel Fund. Details are available at Forthcoming LSST-related Meetings .

Note that the current list of forthcoming meeting is always available on the Relevant Meetings page. You may also wish to check information held on the LSST organisation website LSST-organised events and the LSST Corporation website.

George Beckett

Announcements

If you have significant announcements that are directly relevant to LSST:UK and would like to share the announcement in a future newsletter, please contact the LSST:UK project managers.