HD80606b. The exoplanet – those planets orbiting a star other than our sun – is located in front of the constellation Ursa Major, 190 light-years away. This gas giant, which belongs to the category of hot Jupiter, is, however, a needle – rather a micro-powder – in the straw that is the Universe.
However, in this direction the James Webb Space Telescope (JWST) will have to turn its instruments around 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 observatory, 1.5 million kilometers from Earth, and was calibrated by its instruments before being fully operational. “Not six months ago”, we waited, at the time of launch, at the European Space Agency (ESA).
With its infrared vision, JWST could make great strides, especially to learn more about the habitat of exoplanets. That’s why Hubble’s big brother is interested in the HD80606b. “Astronomers want to study its atmosphere to better understand the meteorological phenomena that occur there,” says Bruno Guillet, a professor of applied physics at the University of Caen Normandy by day (GREYC lab), an amateur astronomer by night. his garden.
The observation will lead to a scientific article to which Bruno Guillet should refer. Yes Yes. Because Caennais contributed to its success, on its own scale, with other amateurs from all over the world. Scientists will want to observe HD80606b as it passes, “when the exoplanet passes between us and its star,” explains Franck Marchis, a French-American astronomer at the Seti Institute and scientific director of Unistellar, a company with Marseille designing digital telescopes. With the HD80606b, we know that transit takes place every 111 days. “But astronomers who want to observe it need more details to better prepare 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, they asked amateur astronomers to observe an HD80606b transit to determine its ephemeral, duration, etc. The Caennais responded present, with other amateurs from around the world. “It was December 7,” he says.
An invaluable network of small telescopes in the four corners of the globe
The perfect illustration of most amateur astronomers can bring, for Franck Marchis. “In many cases, it is also very useful to have a network of small telescopes, mobile and present all over the world,” he says. It is the assurance that you always have someone to observe an unprecedented event. And to pre-massage the work of professional telescopes. That’s the whole point of Unistellar’s digital telescopes, which are 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 completely new and make exciting observations very quickly. »
Since its release in 2016, Unistellar has gradually created 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 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 since the proximity of these planets to their star is so great that their light is completely drowned in it. “To do this, Tess locates and observes their passage, the moment we see the shadow of the celestial body take shape and the light intensity of its star decreases, making it easier to observe. But one observation is not enough to prove that we have an exoplanet in front of our eyes. “We have to observe other of these transits, which Tess does not have time to do; με unlike amateur astronomers,” says Franck Marchis. Thus, the space telescope has identified almost 10,000 possible exponential values, including 5,000 that were later confirmed. Do the same for the other half. This meticulous work also indirectly benefits JWST, as the telescope will focus on the most interesting exoplanets Tess has identified.
Do not waste valuable time JWST
Other similar amateur contributions to JWST success could follow, believes Franck Marchis. A certainty: “Time with a telescope” on James Webb will be very valuable as demand is strong, says Franck Marchis. There is no question of wasting time turning it, for example, two hours much earlier to an exoplanet that has not yet begun to pass. »
While waiting for the needs to become clearer, amateur astronomers already have a lot to do with the ongoing participatory science programs. By early May, Unistellar is calling on its community to focus their telescopes on comet C / 2021 O3. Coming from the Oort cloud, 100,000 astronomical units from us (far, far away), “it is currently passing through our solar system and is likely to be visible throughout May,” suggests 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.
Aside from exoplanets, the interstellar community’s other big hobby – 395 observations last year – is asteroid observation. “The moment they are between us and their star,” explains Franck Marchis. 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. In particular, that of the detective Lucy, who left on October 16 to visit an asteroid in the main belt (between Mars and Jupiter) – 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 improve its orbit, to know when to point this or that instrument to an interesting part of the asteroid,” says Franck Marchis. .