Gravitational Microlensing Archives

November 12, 2023November 12, 2023 by Matt Williams

Gaia is so Accurate it Can Predict Microlensing Events

ESA/Gaia/DPAC; CC BY-SA 3.0 IGO. Acknowledgement: A. Moitinho.

The ESA’s Gaia Observatory continues its astrometry mission, which consists of measuring the positions, distances, and motions of stars (and the positions of orbiting exoplanets) with unprecedented precision. Launched in 2013 and with a five-year nominal mission (2014-2019), the mission is expected to remain in operation until 2025. Once complete, the mission data will be used to create the most detailed 3D space catalog ever, totaling more than 1 billion astronomical objects – including stars, planets, comets, asteroids, and quasars.

Another benefit of this data, according to a team of researchers led by the Chinese Academy of Sciences (CAS), is the ability to predict future microlensing events. Similar to gravitational lensing, this phenomenon occurs when light from background sources is deflected and amplified by foreground objects. Using information from Gaia‘s third data release (DR3), the team predicted 4500 microlensing events, 1664 of which are unlike any we have seen. These events will allow astronomers to conduct lucrative research into distant star systems, exoplanets, and other celestial objects.

November 6, 2023November 6, 2023 by Evan Gough

Roman Could Finally Tell Us if Primordial Black Holes Exist

An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes the direct collapse to a black hole. Credit: Aaron Smith/TACC/UT-Austin.

When the Universe erupted into existence with the Big Bang, all of its matter was compressed into a tiny area. Cosmologists theorize that in some regions, subatomic matter may have been so tightly packed that matter collapsed into primordial black holes. If these primordial black holes exist, they’re small, and they could be hiding among the population of free-floating planets.

July 28, 2023July 28, 2023 by Matt Williams

If Rogue Planets are Everywhere, How Could We Explore Them?

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Image Credit: ESO/M. Kornmesser/S. Guisard

At one time, astronomers believed that the planets formed in their current orbits, which remained stable over time. But more recent observations, theory, and calculations have shown that planetary systems are subject to shake-ups and change. Periodically, planets are kicked out of their star systems to become “rogue planets,” bodies that are no longer gravitationally bound to any star and are adrift in the interstellar medium (ISM). Some of these planets may be gas giants with tightly bound icy moons orbiting them, which they could bring with them into the ISM.

Like Jupiter, Saturn, Uranus, and Neptune, these satellites could have warm water interiors that might support life. Other research has indicated that rocky planets with plenty of water on their surfaces could also support life through a combination of geological activity and the decay of radionuclides. According to a recent paper by an international team of astronomers, there could be hundreds of rogue planets in our cosmic neighborhood. Based on their first-ever feasibility analysis, they also indicate that deep space missions could explore these unbound objects more easily than planets still bound to their stars.

July 24, 2023July 25, 2023 by Laurence Tognetti

There Could be Trillions of Rogue Planets Wandering the Milky Way

Artist's rendition of an ice-encrusted, Earth-mass rogue planet free-floating through space. (Credit: NASA’s Goddard Space Flight Center)

A pair of new studies set to be published in The Astronomical Journal examine new discoveries in the field of rogue planets, which are free-floating exoplanets that drift through space unbound by the gravitational tug of a star. They can form within their own solar system and get ejected, or they can form independently, as well. The first study examines only the second discovery of an Earth-mass rogue planet—the first being discovered in September 2020—while the second study examines the potential number of rogue planets that could exist in our Milky Way Galaxy.

March 24, 2023March 24, 2023 by Evan Gough

A Rogue Earth and Neptune Might Have Been Found in Older Data

An artist's illustration of a rogue planet, dark and mysterious. Image Credit: NASA

Scientists have found what appear to be rogue planets hidden in old survey data. Their results are starting to define the poorly-understood rogue planet population. In the near future, the Nancy Grace Roman Space Telescope will conduct a search for more free-floating planets, and the team of researchers developed some methods that will aid that search.

June 11, 2022June 11, 2022 by Nancy Atkinson

Hubble Pins Down the Mass of a Potential Free-Floating Black Hole That’s 5,000 Light-Years Away

This is an artist’s impression of a black hole drifting through our Milky Way galaxy. The black hole is the crushed remnant of a massive star that exploded as a supernova. The surviving core is several times the mass of our Sun. The black hole traps light because of its intense gravitational field. The black hole distorts the space around it, which warps images of background stars lined up almost directly behind it. This gravitational "lensing" effect offers the only telltale evidence for the existence of lone black holes wandering our galaxy, of which there may be a population of 100 million. The Hubble Space Telescope goes hunting for these black holes by looking for distortion in starlight as the black holes drift in front of background stars. Credit: ESA

Earlier this year, astronomers used microlensing and the Hubble Space Telescope to detect, for the first time, a rogue black hole that is about 5,000 lightyears away from Earth. Now, with more precise measurements, they have been able to determine an approximate mass of this hard-to-detect object. However, the surprisingly low mass means there’s a chance this object may not actually be a black hole.

April 6, 2022April 6, 2022 by Evan Gough

Digging Through Kepler Data Turns Up a Near Twin of Jupiter

The exoplanet, K2-2016-BLG-0005Lb, is almost identical to Jupiter in terms of its mass and its distance from its sun was discovered using data obtained in 2016 by NASA's Kepler space telescope. The exoplanetary system is twice as distant as any seen previously by Kepler, which found over 2,700 confirmed planets before ceasing operations in 2018. Image Credit: Specht et al. 2022.

NASA’s Kepler planet-hunting spacecraft was deactivated in November 2018, about ten years after it launched. The mission detected over 5,000 candidate exoplanets and 2,662 confirmed exoplanets using the transit method. But scientists are still working with all of Kepler’s data, hoping to uncover more planets in the observations.

A team of researchers have announced the discovery of one more planet in the Kepler data, and this one is nearly a twin of Jupiter.

July 8, 2021July 8, 2021 by Andy Tomaswick

Multiple Earth-Mass Rogue Planets Have Been Discovered Drifting Through the Milky Way

Last year we reported on how the Roman Space Telescope’s backers hoped it would be able to detect rogue planets using a technique called “microlensing”. Now, a team led by Iain McDonald, then at the University of Manchester, beat them to the punch by finding a few examples of Earth-sized rogue planets using data from an already aging space telescope – Kepler.

April 18, 2021April 18, 2021 by Andy Tomaswick

Roman Space Telescope Will Also Find Rogue Black Holes

In the past we’ve reported about how the Roman Space Telescope is going to potentially be able to detect hundreds of thousands of exoplanets using a technique known as “microlensing”. Exoplanets won’t be the only things it can find with this technique though – it should be able to find solitary black holes as well.

April 4, 2021April 4, 2021 by Andy Tomaswick

Roman Telescope Could Turn up Over 100,000 Planets Through Microlensing

Recently we reported on a haul of 2,200 new exoplanets from the 2 year primary mission of the Transiting Exoplanet Survey Satellite (TESS). But that is just the tip of the iceberg in terms of exoplanet hunting. If calculations from NASA are correct the Nancy Grace Roman Space Telescope could detect up to 100,000 new exoplanets when it launches in 2025.