Gaia Archives

November 20, 2024November 20, 2024 by Evan Gough

Main Sequence and White Dwarf Binaries are Hiding in Plain Sight

This ALMA image shows the binary HD101584. The pair of stars share a common envelope, and are surrounded by complex clouds of gas. Image Credit: By ALMA, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=86644758

Some binary stars are unusual. They contain a main sequence star like our Sun, while the other is a “dead” white dwarf star that left fusion behind and emanates only residual heat. When the main sequence star ages into a red giant, the two stars share a common envelope.

This common envelope phase is a big mystery in astrophysics, and to understand what’s happening, astronomers are building a catalogue of main sequence-white dwarf binaries.

October 16, 2024October 16, 2024 by Mark Thompson

Giant Cluster is Spitting Out Massive Stars

Artistic impression of star cluster R136 with runaway stars. Credit: Danielle Futselaar, James Webb Space Telescope/NIRCam - NASA, ESA, CSA and STScI

We live inside the Milky Way galaxy which is joined as it drifts through space by two satellite galaxies, the Magellanic Clouds. A star cluster in the Large Magellanic Cloud known as R136 has been the subject of a fascinating discovery. A team of astronomers have discovered 55 high-speed stars that have been ejected from the cluster. The discovery was made using the Gaia satellite and it seems up to a third of stars from the cluster have been ejected in the last century.

September 19, 2024September 19, 2024 by Mark Thompson

Building a Worldwide Map of Light Pollution

As someone that has always lived in the UK countryside I am no stranger to the glory of a dark star-filled sky. Sadly 60% of the world’s population has already lost access to the night sky thanks to light pollution. Across Europe and the US that number climbs to nearer 80%. A team of researchers want to try and track the growth of light pollution and to that end have developed an inexpensive sensor made from “off-the-shelf” parts. Their hope is that people around the world will build and install these sensors to share their data enabling them to track the spread of light pollution. If you’ve got technical skills, this could be a fun project.

August 12, 2024August 12, 2024 by Andy Tomaswick

Astronomers Use Artificial Intelligence To Find Elusive Stars “Gobbling Up” Planets

We recently reported on how the mountains of data produced by astronomical instruments are “perfect for AI.” We’ve also started reporting on several use cases for different AI algorithms. Now, a team of researchers from the University of Texas has developed a new use case that focuses on discovering the interior makeup of exoplanets by looking at a specific type of star.

July 8, 2024July 8, 2024 by Mark Thompson

Mapping the Milky Way’s Dark Matter Halo

The Galactic disk warp "dances gracefully" under the torque of the dark matter halo (an artistic impression created by Kaiyuan Hou and Zhanxun Dong from the School of Design, Shanghai Jiao Tong University).

Anytime astronomers talk of mapping the Milky Way I am always reminded how tricky the study of the Universe can be. After all, we live inside the Milky Way and working out what it looks like or mapping it from the inside is not the easiest of missions. It’s one thing to map the visible matter but mapping the dark matter is even harder. Challenges aside, a team of astronomers think they have managed to map the dark matter halo surrounding our Galaxy using Cepheid Variable stars and data from Gaia.

May 29, 2024May 29, 2024 by Mark Thompson

There’s Another, More Boring Explanation for those Dyson Sphere Candidate Stars

Dyson Spheres have been a tantalising digression in the hunt for alien intelligence. Just recently seven stars have been identified as potential candidates with most of their radiation given off in the infrared wavelengths. Potentially this is the signature of heat from a matrix of spacecraft around the star but alas, a new paper has another slightly less exciting explanation; dust obscured galaxies.

May 10, 2024May 10, 2024 by Mark Thompson

Does the Milky Way Have Too Many Satellite Galaxies?

The Large and Small Magellanic Clouds are well known satellite galaxies of the Milky Way but there are more. It is surrounded by at least 61 within 1.4 million light years (for context the Andromeda Galaxy is 2.5 million light years away) but there are likely to be more. A team of astronomers have been hunting for more companions using the Subaru telescope and so far, have searched just 3% of the sky. To everyone’s surprise they have found nine previously undiscovered satellite galaxies, far more than expected.

May 9, 2024May 9, 2024 by Evan Gough

Astronomers are on the Hunt for Dyson Spheres

Artist's impression of a Dyson Sphere. The construction of such a massive engineering structure would create a technosignature that could be detected by humanity. Credit: SentientDevelopments.com/Eburacum45

There’s something poetic about humanity’s attempt to detect other civilizations somewhere in the Milky Way’s expanse. There’s also something futile about it. But we’re not going to stop. There’s little doubt about that.

One group of scientists thinks that we may already have detected technosignatures from a technological civilization’s Dyson Spheres, but the detection is hidden in our vast troves of astronomical data.

March 21, 2024March 21, 2024 by Evan Gough

One in Twelve Stars Ate a Planet

When a star eats a planet, it changes the star's metallicity. New research based on co-natal stars shows that one in twelve stars have eaten at least one planet. Image Credit: International Gemini Observatory/NOIRLab/NSF/AURA/M. Garlick/M. Zamani

That stars can eat planets is axiomatic. If a small enough planet gets too close to a large enough star, the planet loses. Its fate is sealed.

New research examines how many stars eat planets. Their conclusion? One in twelve stars has consumed at least one planet.

March 18, 2024March 18, 2024 by Evan Gough

This New Map of 1.3 Million Quasars Is A Powerful Tool

This figure from the research shows the sky distribution of the new Quaia quasar catalogue in Galactic coordinates and is displayed using a Mollweide projection. The grey region across the center is the Milky Way, a blind spot in the Quaia catalogue. Image Credit: K. Storey-Fisher et al. 2024

Quasars are the brightest objects in the Universe. The most powerful ones are thousands of times more luminous than entire galaxies. They’re the visible part of a supermassive black hole (SMBH) at the center of a galaxy. The intense light comes from gas drawn toward the black hole, emitting light across several wavelengths as it heats up.

But quasars are more than just bright ancient objects. They have something important to show us about the dark matter.