HD80606b. L ‘ extrasolar planet Those planets that orbit a star other than our Sun – lie in the foreground of the constellation Ursa Major, 190 light-years away from us. This giant gas is classified In the category of Hot JupitersShe is, however, a needle – rather a fine dust – in the haystack that is the universe.
However it is this is that James Webb Space Telescope (JWST) Her instruments should be pointing toward October for one of her first observations. Departing on December 25, the largest and most powerful telescope ever sent into space arrived a month later at its observation center, 1.5 million kilometers from Earth, calibrated from its instruments before it was fully operational. “Not before six months”, It was expected at launchto me European Space Agency (ESA).
Exoplanet hunters
With its infrared vision, JWST could allow for significant advances, particularly to learn more about the habitability of exoplanets. That’s why Hubble’s older brother is interested in the HD80606b. “Astronomers want to study its atmosphere to better understand the meteorological phenomena that are there,” Bruno Gillette, an instructor and researcher in applied physics at the University of Caen-Normandy said that day. (GREYC Lab)Astronomy enthusiasts at night from his garden.
The observation will lead to a scholarly article in which Bruno Gillet should be mentioned. Yes Yes. Because Caennais contributed to her success, on her own scale, with other hobbyists from around the world. Scientists will want to monitor HD80606b as it transits, “when an exoplanet passes between us and its star,” he explains. Frank Marches, French-American astronomerresearcher in City Institute and scientific director Unistellar, company of Marseille Who designs digital telescopes. With HD80606b, we know that transits happen every 111 days. “But astronomers who wanted to observe it needed more detail to better prepare this observation and avoid directing the JWST two hours prematurely or too late,” Bruno Guillet continues. NASA watching an exoplanet, a participatory science program of the US Space Agency, asked amateur astronomers to observe the transit of HD80606b to determine its ephemeris, how long it takes, etc. Caennais present answered with other buffs from all over the world. “It was last December 7,” he says.
An invaluable network of small telescopes located in the four corners of the world
The perfect illustration of what amateur astronomers can bring, by Frank Marches. He says, “In many cases, it is also very useful to have a network of small, mobile telescopes located everywhere in the world. It is always a guarantee that someone will be there to observe an unprecedented event. And to pre-make the task of professional telescopes. This is the whole purpose of Unistellar digital telescopes, which are ideal for citizen science. “All you have to do is enter the celestial coordinates of the object you want to observe so the telescope will automatically point in that direction,” continues Frank Marches. You can be a complete novice and very quickly make great feedback. »
Since its launch in 2016, Unistellar has gradually built a community of 5,000 enthusiasts, of whom Bruno Guillet is one of the most active members. “Last year, this community made 413 observations of exoplanets, including one observation located more than 2,700 light-years away,” Unistellar said.
Again, the idea is to help scientists. In April 2018, NASA launched into orbit TESS, a space telescope too, dedicated to the search for exoplanets. It’s not easy because these planets are so close to their star that their light is completely immersed in it. “To do that, Tess discovers and watches its passage, The moment we will see the shadow of the orb forming and the luminous intensity of its star decreases, making it easier to notice. But one observation is not enough to prove the existence of an exoplanet before our eyes. “We have to note other transits, which Tess doesn’t have time to make…unlike amateur astronomers, points out Frank Marches. Thus the space telescope has identified nearly 10,000 possible exoplanets, including 5,000 that have been confirmed later. Do the same. The thing for the other half.This careful work also indirectly benefits JWST, as the telescope will be pointed at the most interesting exoplanets that Tess has spotted.
Don’t waste precious JWST time
Frank Marches believes that other similar contributions from amateurs to JWST’s success can follow. One certainty: “Telescope time” on James Webb will be very valuable because the demand is strong, as Frank Marshes points out. No doubt wasting time by pointing it, say, two hours too early toward an exoplanet that has not yet begun its transit. »
While waiting for the needs to become more clear, amateur astronomers already have a lot to do with ongoing participatory science programs. Until early May, Unistellar invites its community to point its telescopes at it Comet C / 2021 O3. at Oort cloud, At 100,000 AU from us (very, very far away), “it’s currently passing through our solar system and likely visible throughout May, notes Frank Marches. Not only should the spectacle be dazzling, but it would also be scientifically interesting to observe the comet’s behavior.” When it approaches our sun, the collected data will be sent to the Seti Institute, which hopes to learn more about the comet’s internal composition.
In addition to exoplanets, the other big hobby of the interstellar community – 395 observations last year – is observing asteroids. “At a specific moment, when they find themselves between us and their star, Frank Marches identifies. From Earth, we can then see the shadow of the asteroid, which makes it possible to better determine its size and shape. Very useful information for the success of space missions. Especially thatLucy probe, which departed on October 16 To visit an asteroid in the main belt (between Mars and Jupiter) – there will be in 2025 – then seven Trojan asteroids Jupiter. “It will pass relatively quickly over these objects, so NASA needs as much information as possible to improve its trajectory, to know when to point this or that instrument on an interesting part of the asteroid,” says Frank Marches.
