Tess found 3i/Atlas two months earlier than it was found – it was even energetic on the time

One of the advantages that so many telescopes observe large parts of the sky is that when astronomers find something interesting, there are probably pictures of it before there are officially sitting in the data archives of other satellites that nobody should look at. This was certainly the case for our latest interstellar visitors 3i/Atlas, which, although it was discovered in early July, was already visible in other telescopes in May. We previously found Vera Rubin’s detection of 3i/Atlas before the official found, and now a new paper has brought the Interstellar object back from Tess to the beginning of May – and it looks as if it could have been “active” at that time.

The Transiting Exoplanet Survey Satellite (Tess) is not designed in such a way that it finds interstellar visitors or something that is weak on this matter. As the name suggests, it is designed in such a way that it looks at stars (which are light) and see how exoplanets cross in front of them and observe the tavern’s light curve as they do. However, data is data, and since Tess happened to look at part of the sky in which 3I/Atlas should be at the beginning of this year, the researchers Adina Feinstein and Darryl Seligman from the state of Michigan and John Noonan from Auburn decided whether they could find any data in the telescopic archives.

It turned out that in the course of two separate observation times until May 7, 2025 to May 7, 2025. Since Tess records an image every 200 seconds and 3i/Atlas moves much faster than the traditional stars that Tess viewed, the team had to use a technology called “shift stacking”. They predicted where the interstellare object (ISO) would be in every picture, the images moved so that the ISO is in the same place in every picture, and then stacked the several images to get a clear signal of an object that would otherwise be weak in a single picture to find it.

https://www.youtube.com/watch?v=7crlHPD87UG

Fraser discusses how 3i/Atlas signs show that it spends a lot of other things what is to be expected – water.

3i/Atlas started the observation time with about 6.35 Au and moved to around 5.47 au on June 2 to the end of a second window. During this time, its river rose by factor 5, although the removal of the distance would only have increased brightness by 1.5

There have already been numerous speculations about what could cause some of the more interesting features of 3i/Atlas, from errors in data acquisition to the object itself is extraterrestrial technology. However, the authors have a much more everyday explanation for this apparently bizarre event – ISO has probably exceeded “hypervolatile” materials such as carbon dioxide and carbon monoxide. These have a much higher sublimation point than water ice and can lead to a significant increase in brightness, but most comets in our own solar system have no hypervolatile, so that they would not have the same dramatic increase in brightness, so far from the sun. For the researchers, this is another data point that comets from other solar systems probably have a completely different composition than those bound to us.

In order to find even more differences, they also tried to look at the rotation period of the ISO core. However, there was not enough a clear signal to describe whether the core actually moved or not. This was most likely caused by a coma that made noticeable characteristics hidden, which made it difficult for Tess to recognize changes in the brightness caused by its rotation.

https://www.youtube.com/watch?v=4bx96ikafhs

Fraser discusses 3i/Atlas more generally when it has been discovered for the first time.

While we continue to examine every new interstellar object that comes on our way, we will find out more and more about you. This paper contributes to this body of knowledge, and it will undoubtedly come even more when astronomers start to search old data for any telescope that you can try to unlock the secrets of our puzzling visitors.

Learn more:

A. Feinstein, J Noonan and D. Seligman – Observations of 3i/Atlas from Tess suggests a possible distant activity

Ut – 3i/Atlas publishes very active water

Ut – apparently Vera Rubin took pictures of 3i/Atlas before it was even discovered

Ut – persecution of the interstellar objects 1i/’oumuamua, 2i/borisov and 3i/atlas to their source