Microlensing Observations in Astrophysics (MOA) is a collaborative project between researchers in New Zealand
and Japan,
led by Professor Yasushi Muraki of
Nagoya University
, abbreviated to or NU, is a Japanese national research university located in Chikusa-ku, Nagoya.
It was established in 1939 as the last of the nine Imperial Universities in the then Empire of Japan, and is now a Designated National Universit ...
.
They use
microlensing
Gravitational microlensing is an astronomical phenomenon caused by the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronome ...
to observe
dark matter
In astronomy, dark matter is an invisible and hypothetical form of matter that does not interact with light or other electromagnetic radiation. Dark matter is implied by gravity, gravitational effects that cannot be explained by general relat ...
,
extra-solar planets, and
stellar atmosphere
The stellar atmosphere is the outer region of the volume of a star, lying above the stellar core, radiation zone and convection zone.
Overview
The stellar atmosphere is divided into several regions of distinct character:
* The photosphere, whi ...
s from the
Southern Hemisphere. The group concentrates especially on the detection and observation of
gravitational microlensing
Gravitational microlensing is an astronomical phenomenon caused by the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronom ...
events of high magnification, of order 100 or more, as these provide the greatest sensitivity to extrasolar planets. They work with other groups in
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
, the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
and elsewhere. Observations are conducted at New Zealand's
Mt. John University Observatory using a
reflector telescope built for the project.
In September 2020, astronomers using
microlensing techniques reported the detection, for the first time, of an
earth-mass rogue planet
A rogue planet, also termed a free-floating planet (FFP) or an isolated planetary-mass object (iPMO), is an interstellar object of planetary mass which is not gravitationally bound to any star or brown dwarf.
Rogue planets may originate from ...
unbounded by any star, and free floating in the
Milky Way galaxy
The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are ...
.
In January 2022 in collaboration with
Optical Gravitational Lensing Experiment
The Optical Gravitational Lensing Experiment (OGLE) is a Polish astronomy, astronomical project based at the University of Warsaw that runs time-domain astronomy, a long-term variability sky survey (1992–present). The main goals are the detecti ...
(OGLE) they reported in a preprint the first
rogue BH while there have been others candidates
this is the most solid detection so far as their technique allowed to measure not only the amplification of light but also its deflection by the BH from the microlensing data.
MOA telescope mirror images
Image:MOA telescope underside of main mirror.jpg , Underside of main mirror
Image:MOA telescope secondary.jpg , Camera assembly
Image:MOA telescope mirror.jpg , Main mirror, side view
Planets discovered
The following planets have been announced by this survey, some in conjunction with other surveys.
See also
*
Optical Gravitational Lensing Experiment
The Optical Gravitational Lensing Experiment (OGLE) is a Polish astronomy, astronomical project based at the University of Warsaw that runs time-domain astronomy, a long-term variability sky survey (1992–present). The main goals are the detecti ...
or ''OGLE'', a similar microlensing survey
*
List of extrasolar planets
A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but ...
References
External links
MOA websiteMicroFUN - Microlensing Follow-Up Network
{{Portal bar, Astronomy, Stars, Outer space, Solar System
Astronomical surveys
Experiments for dark matter search
Gravitational lensing
Exoplanet search projects