HD80606b. The exoplanet, those planets that revolve around a star other than our sun, is on the front leg of the constellation Ossa Major, 190 light-years from us. This gas giant, classified in the category of hot Jupiter, is nevertheless a needle, rather a micropole, in the barn that is the Universe.
However, this is where the James Webb Space Telescope (JWST) should point its instruments in October for one of its first observations. Leaving on December 25, the largest and most powerful telescope ever sent into space arrived a month later at its observation site, 1.5 million kilometers from Earth, and calibrated with its instruments before be fully operational. “Not before six months”, we expected, at the time of launch, at the European Space Agency (ESA).
With its infrared vision, JWST could make great strides, particularly in learning more about the habitability of exoplanets. That’s why Hubble’s older brother is interested in HD80606b. “Astronomers want to study their atmosphere to better understand the meteorological phenomena at play,” says Bruno Guillet, a professor of applied physics at the University of Caen by day, an amateur astronomer by night, from his garden.
The observation will lead to a scientific article in which Bruno Guillet should be mentioned. Yeah yeah. Because Caennais contributed to its success, on its own scale, with other fans around the world. Scientists will want to observe HD80606b during its transit, “when the exoplanet passes between us and its star,” says Franck Marchis, a French-American astronomer, researcher at the Seti Institute and scientific director of Unistellar, a Marseille-based company that designs digital. telescopes. With HD80606b, we know that traffic is every 111 days. “But astronomers who want to observe it needed more details to better prepare for this observation and avoid directing the JWST two hours too early or too late,” continues Bruno Guillet. In November, through the NASA Exoplanet Watch, a participatory science program of the US space agency, amateur astronomers were asked to observe a transit of HD80606b to specify its ephemeris, time of its duration, etc. . The Caennais responded present, with other fans from around the world. “It was last December 7,” he says.
An invaluable network of small telescopes present in the four corners of the globe
The perfect illustration of the most that amateur astronomers can provide, for Franck Marchis. “In many cases, it is also very useful to have a network of small, mobile telescopes that are present all over the world,” he says. It is the security of always having someone to watch an unprecedented event. And to pre-chew the work of professional telescopes. That’s the whole point of Unistellar digital telescopes, perfect for citizen science. “All you have to do is enter the celestial coordinates of the object you want to observe so that the telescope automatically points in that direction,” continues Franck Marchis. You can be a complete neophyte and make fascinating observations very quickly. »
Since its launch in 2016, Unistellar has been gradually consolidating a community of 5,000 enthusiasts, of which Bruno Guillet is one of the most active members. “Last year, this community made 413 observations of exoplanets, including one located more than 2,700 light-years away,” Unistellar said.
Again, the idea is to help scientists. In April 2018, NASA launched Tess, a space telescope also dedicated to the search for exoplanets. It is not easy because the proximity of these planets to their star is so great that their light is completely drowned out. “To do this, Tess detects and observes its transit, the moment we see how the shadow of the celestial body takes shape and the light intensity of its star decreases, facilitating its observation. But a single observation is not enough to certify that we have an exoplanet before our eyes. “We have to look at other of these transits, which Tess doesn’t have time to do … unlike amateur astronomers,” says Franck Marchis. Do the same for the other half.This meticulous work also indirectly benefits the JWST, as the telescope will aim at the most interesting exoplanets detected by Tess.
Don’t waste precious time JWST
Franck Marchis believes other similar contributions from fans to the success of the JWST could follow. One thing is for sure: “The” telescope time “for James Webb will be very precious, as demand is strong, says Franck Marchis. an exoplanet that has not yet begun its transit. ”
While waiting for the needs to become clearer, amateur astronomers already have a lot to do with ongoing participatory science programs. Until the beginning of May, Unistellar is asking its community to aim its telescopes at comet C / 2021 O3. Coming from the Oort cloud, 100,000 astronomical units away from us (far, far away), it is currently passing through our solar system and is likely to be visible throughout May, says Franck Marchis. Not only should the spectacle be dazzling, but it will also be scientifically interesting to observe the comet’s behavior as it approaches our Sun. The data collected will be sent to the Seti Institute, which hopes to learn more about the comet’s internal composition.
In addition to exoplanets, the other major hobby of the interstellar community – 395 observations last year – is the observation of asteroids. “At a precise moment, when they are between us and their star,” says Franck Marchis. From Earth, we can then see the shadow of the asteroid, which allows us to better determine its size and shape. Very useful information for the success of space missions. Specifically, that of the Lucy spacecraft, which left on October 16 to visit an asteroid in the main belt (between Mars and Jupiter) – it will be there in 2025 -, then seven Trojan asteroids from Jupiter. “It will pass over these objects relatively quickly, so NASA needs as much information as possible to refine its trajectory, to know when to point this or that instrument at an interesting part of the asteroid,” says Franck Marchis.