In the second panel Sirius has been subtracted, though a lot of scattered light remains in the image. The third panel is the same image with all Gaia-detected stars over-plotted as red points. The larger of the two clusters was hiding close to Sirius, the brightest star in the night sky.
Images taken close to stars this bright are often hard to use: the reflection and refraction of its light creates blurs and smudges on the surrounding image, as you can see in Figure 3. Because Gaia takes numerous images of each region of sky, these effects average out in their data allowing the nearby cluster to be identified for the first time.
The cluster appears to be dominated by old stars, with a particularly prominent number of red giants, as would be expected from a globular cluster. The team measured a distance to the cluster of parsecs well within the halo of the Milky Way and a size of 9 parsecs also typical of globular clusters; for comparison, a parsec is roughly the distance between us and our closest star, Proxima Centauri.
They estimate the total mass of the cluster as 14, times the mass of our sun — so clearly these stars are densely packed! The second cluster, Gaia 2, is smaller than Gaia 1 at 3 parsecs across, and even older at around 10 billion years. It has a distance of parsecs. Given this size, age, and appearance, they believe that this is another globular cluster.
With better images, it will be possible to find out more about these clusters and confirm some of their less certain details. Beyond this, the discovery of these two new objects highlights the revolutionary potential Gaia has in this field.
How Gaia could help find Dyson spheres
With the release of future sets of Gaia data, which will include colours, distances, and movements for each star it targets, it is clear that many more galactic satellites will be revealed. The next data release is scheduled for early next year, so until then, watch this space! Email Address. A pair of new satellites of the Galaxy Authors: S.
Koposov, V. Belokuro, G.
- ESA Science & Technology: How do you find a star cluster? Easy, simply count the stars;
- From One Satellite to Another: Finding Clusters with Gaia.
- Finding Gaia | Of a Star?
About the Author. I work with white dwarf binary systems, and in particular with AM CVn-type binaries.
In my spare time I enjoy writing of all kinds, as well as playing music, board games and rock climbing. For more things written by me, take a look at my website.
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Follow us on Twitter Follow astrobites. Illustration of how Gaia is measuring the distances to most stars in the Milky Way with unprecedented accuracy. Image via S. Of course, figuring out if any of these could actually be Dyson sphere candidates required further analysis. This alone left only six possible candidates. Those in turn were then narrowed down to only two, after eliminating four candidates due to problems with the data itself. Image via D. So … has the first Dyson Sphere been found?
No other glitch-related weirdness was found in the data, but the star was also found to be a binary system consisting of two stars the other being a small white dwarf which might explain the results — but none of that is certain yet. Additional study of the star will be required, including using future Gaia data releases, to determine what is really happening here. To shed light on the properties of objects in this outlier population, we present follow-up high-resolution spectroscopy for one of these stars, the late F-type dwarf TYC The spectrophotometric distance of this object is about twice that derived from its Gaia parallax, and there is no detectable infrared excess.
While our analysis largely confirms the stellar parameters and the spectrophotometric distance inferred by RAVE, a plausible explanation for the discrepant distance estimates of this object is that the astrometric solution has been compromised by an unseen binary companion, possibly a rather massive white dwarf. This scenario can be further tested through upcoming Gaia data releases.
Read more: What is a Dyson sphere? A handy illustrated guide to Dyson spheres — massive structures which could be built to surround a star and harness its energy by an advanced alien civilization. Bottom line: Discovering an actual Dyson sphere, or something similar, would be incredible.
Gaia: Mapping a Billion Stars
This new study proposes a new method of searching which shows some promise. Regardless, this new search method will prove valuable in future searches as well. While in school he was known for his passion for space exploration and astronomy. He started his blog The Meridiani Journal in , which was a chronicle of planetary exploration. In , the blog was renamed as Planetaria. While interested in all aspects of space exploration, his primary passion is planetary science.
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In , he started writing about space on a freelance basis, and now currently writes for AmericaSpace and Futurism part of Vocal. Amazing June for noctilucent clouds. South American solar eclipse on July 2. Help Support EarthSky with a Donation! EarthSky Updates on your cosmos and world. Paul Scott Anderson. Asteroid Day is June 30 2 days ago. ESA will head for the double asteroid, too 2 days ago. Today's Image Amazing June for noctilucent clouds.