Microlensing programs at LCO have been a major contributor to high-impact science since the institute was established. These programs, run by a diverse team of scientists from LCO and partner institutes around the world, have detected some of the lowest-mass exoplanets known to date, as well as other objects of scientific interest such as Brown Dwarfs and Black Holes.
2005-2013: RoboNet
The RoboNet project used the Faulkes and Liverpool telescopes to provide critical follow-up observations of ongoing microlensing events alerted by the OGLE and MOA surveys. This project contributed to the discovery of 5 out of the first 6 cool planets discovered by microlensing, and also pioneered the development of fully-automated target selection, scheduling optimization on the robotic telescope network, and real-time processing of observations. In 2012, the system was expanded to incorporate Lucky Imaging technology, and in 2013 it began using the then-newly-deployed LCO 1m telescopes.
2014-2016: RoboNet & the LCO 1m Network
The completion of the LCO 1m telescope network in the southern hemisphere, made it possible to provide continuous 24/7 coverage of microlensing events when weather conditions allowed. This was enhanced through a partnership with the University of St Andrews that made it possible to add additional 1m telescopes to all three southern sites in Chile, South Africa and Australia. The infrastructure developed in previous years was updated to support more responsive scheduling and increased flexibility in handling a larger and rapidly evolving target list. This project also saw the development of the Target and Observation Manager (TOM) system, specifically designed for the microlensing program. The experience gained from building this system would later prove crucial in the development of the LCO TOM system.
In order to run the RoboNet project, the microlensing team developed a database-driven system to keep track of the many targets and observations of this highly dynamic observing program. This system took advantage of the original eSTAR system developed in the UK to send observation requests to the telescopes.
This system proved to be essential to the success of the program, and other science teams both at LCO and outside subsequently developed similar systems to manage their own research programs: Target and Observation Managers, or TOM systems. Rather than have every research team reinvent this wheel, LCO developed the TOM Toolkit, an open-source package which anyone can use to build a TOM for their own project.
Microlensing became the focus of one of the first generation of LCO Key Projects, made possible with substantial contributions from St Andrews and LCO.
2017 - 2020: ROME/REA, K2/Campaign 9 and the WFIRST Microlensing Science Investigation Team
The ROME/REA project used the wider-field capabilities of the newly deployed Sinistro cameras on the LCO network to conduct a multi-wavelength survey, with reactive follow-up observations focused on anomaly characterization.
Since virtually all known microlensing events at this time were discovered in a relatively small region of the Galactic Bulge, the LCO team switched from the responsive follow-up strategy of RoboNet to a survey of 20 fields in the Galactic Bulge, including regions of the Bulge observed by the K2 Mission during Campaign 9. Observations were made every few hours in SDSS-g,r,i filters, providing longer timeseries observations of each event, which helps to constrain the microlensing parallax. The color observations are used to estimate the extinction in the field and the spectral type of the source star of microlensing events.
This project contributed to the discovery of several new planets and produced a photometric time-series catalogue containing over 5 million sources. It also oversaw the development of the open-source pyDANDIA difference imaging pipeline and the pyLIMAmicrolensing modeling software package.
The LCO team adapted their robotic system in support of the K2 Campaign 9 by sending a real-time feed of all microlensing alerts discovered in the K2/C9 field to NASA's Exoplanet Archive. This platform was used to coordinate community-wide follow-up of these events.
LCO staff also contributed to the WFIRST Microlensing Science Investigation Team (MicroSIT) was lead by Scott Gaudi (The Ohio State University). In particular the LCO microlensing team established the Microlensing Source website to provide information for researchers interested in microlensing as well as resources for educators. The LCO team also supported the Sagan Workshop on microlensing in 2017.
2020 - 2023: OMEGA Key Project
The OMEGA project builds on the infrastructure developed during previous microlensing projects to harvest and process transient alert streams from multiple surveys such as Gaia, ZTF, OGLE, and MOA. Its fully-automated system is optimized to identify new microlensing events in real-time, assess their sensitivity to planets, and request follow-up observations on the LCO network to characterize the signals. In addition to planets, OMEGA also responds to Brown Dwarf and Black Hole candidate events.
Although the global pandemic interrupted several microlensing surveys, new sources of discoveries had become available. ESA's Gaia Mission continued its program of astrometric and photometric timeseries observations of 1 billion stars in the Milky Way, scanning the entire sky. The mission issues real-time alerts of photometric variable objects discovered in this dataset through the Gaia Alerts System. At the same time, the Zwicky Transient Facility came online, monitoring the northern sky at high cadence and issuing discovery alerts. Both surveys proved that microlensing alerts are no longer confined to the Galactic Bulge, and the OMEGA Key Project delivers follow-up observations of microlensing events discovered by these and other time-domain surveys. You can learn more about the OMEGA Project here.
In order to run the OMEGA project, the team overhauled their previous observing system, and built a new TOM System using LCO's TOM Toolkit, the Microlensing Observing Platform, MOP.