Due to the intrinsically transient nature of microlensing, it is vital that all required observations be obtained while the event is in progress. This is no trivial task because ideally the events need to be continuously observed for a period of days to several weeks, meaning that observations must be acquired from a coordinated set of telescopes spread across several longitudes. Furthermore, the unpredictability of the events and their critical features means observations have to be obtained in rapid response to alerts. To answer these challenges, microlensing has produced a number of pioneering programs designed to provided follow-up observations taken in rapid response to survey discoveries.

Here we give a brief overview of those programs (in alphabetical order), and we refer interested readers to the publications listed on the project websites for an overview of their science contributions.

MicroFUN

Principle InvestigatorAndy Gould, Ohio State University
Website MicroFUN Website
Telescope apertureAn extensive network of facilities with apertures in the range 0.25-1.3m
SitesContributors from up to 25 sites in New Zealand, Australia, Chile, South Africa and USA
Fields of viewRange from a few arcmins to degrees
PassbandsI, V, unfiltered

The MicroFUN group is an outstanding example of partnership between professional and citizen scientist contributors, with targets selected and coordinated by a dedicated team at Ohio State and data gathered by equally dedicated observers around the world.

MiNDSTEp

Principle InvestigatorUffe Jørgensen, Niels Bohr Institute, University of Copenhagen
Websites MiNDSTEp Website
ARTEMiS Website
Telescope aperture1.5m Danish Telescope, 1.2m MONET-N, 1.2m MONET-S, 0.6m Salerno Telescope
SitesESO La Silla, Chile, McDonald Observatory, USA, South African Astronomical Observatory, Salerno Italy
PassbandsV, I

MiNDSTEp combines a range of (manually-operated) telescope resources into a microlensing follow-up network served by a central, automated, target broker, the ARTEMiS system. MiNDSTEp have broken new ground in the use of high-frame-rate lucky imaging cameras to improve the quality of photometry in the densely crowded microlensing fields.

PLANET

Principle InvestigatorJean-Philippe Beaulieu, Institut D'Astrophysique de Paris
Website PLANET Website
Telescope aperture1.3m Greenhill Telescope
SitesHobart, Tasmania, Australia

The PLANET Collaboration pioneered real-time responsive follow-up of microlensing events as early as 1995 and every season since. The group recently commissioned this new observing facility, named in honor of long-time collaborator Prof. John Greenhill.

RoboNet

Principle InvestigatorRachel Street, Las Cumbres Observatory
Website RoboNet Website
Telescope aperture1.0m and 2.0m telescopes of the LCO network, 2.0m Liverpool Telescope
SitesCerro Tololo Inter-American Observatory, Chile, South African Astronomical Observatory, Siding Spring Observatory, Australia, La Palma, Canary Islands
Field of viewLCO 1.0m network, SBIG cameras 15.8x15.8 arcmin, LCO 1.0 network, Sinistro cameras 2
Pixel scale0.26 arcsec/pixel
PassbandsSDSS-i-prime

The RoboNet Team specializes in conducting microlensing follow-up using robotic telescope resources, and developed a ground-breaking fully-automated system to select and prioritize targets, conduct observations and reduce and analyze the data.