The artist’s imprint shows the LTT 9779B near the star as it orbits and illuminates the planet’s super-hot (2000 Kelvin) day side and its toasting night-side (about 1000 K). Credit: Ethan Schmidt
A team led by an astronomer from the University of Kansas has crushed the data NASANo. TESS And the Spitzer Space Telescope for the first time to depict a very unusual type of atmosphere exoplanet Dub a “hot Neptune”
Findings related to the recently discovered planet LTT 9779B were published today in the Astrophysical Journal Letters. The very first spectrum of any planet discovered by TSS in this paper details the atmospheric characteristic, the atmosphere and the first global temperature map of any TSS planet with a warm Neptune, whose emission spectrum is fundamentally different from many large “hot guptars” previously studied.
“For the first time, we measured light coming from a planet that shouldn’t exist,” said Ian Crossfield, KU’s assistant professor of physics and astronomy and lead author of the paper. “The planet is irradiated so intensely by its star that its temperature is over 1,000,000 degrees. Fahrenheit And its atmosphere could have completely evaporated. However, our Spitzer observations show the planet’s atmosphere through infrared light. “
While the LTT 9779B is exceptional, one thing is for sure: people won’t like it there very much.
“For the first time, we measured light coming from a planet that shouldn’t exist,” said Ian Crossfield, an assistant professor of physics and astronomy at KU and lead author of the paper. “The planet is so intensely irradiated by its star that its temperature is over 1,000,000 degrees Fahrenheit and its atmosphere can completely evaporate. Yet, our Spitzer observations show the planet’s atmosphere through infrared light. “Credit: Ethan Schmidt, University of Kansas
“This planet doesn’t have a solid surface, and it’s even hotter than Mercury in our solar system – it will not only melt into the planet’s atmosphere, but will also make platinum, chromium and stainless steel,” Crossfield said. “A year on this planet is less than 24 hours – how fast it whips around the star. It’s a pretty extreme system. “
Hot Neptune LTT9779B, discovered just last year, became one of the first Neptune-sized planets to be discovered by NASA’s All-Sky TESS Planet-Hunting Mission. Crossfield and his co-authors used a technique called “phase curve” analysis to analyze the atmospheric composition of the exoplanet.
The artist’s impression shows the LTT 9779 system measuring approximately, the hot Neptune-sized planet on the left and its brightest, closest star on the right. Traces of planetary protruding material based on intense irradiation of this planet are imaginary but probable. Credit: Ethan Schmidt
“We measure how much infrared light was being emitted by the planet as it rotates 360 degrees on its axis.” “Infrared light tells you something temperature and where are the hot and cold parts of this planet – on Earth, it’s not the hottest at noon; It is the hottest for a few hours at noon. But on this planet, it’s really the hottest time at noon. We have seen that most of the infrared light is coming from part of the planet while its star is directly heading and much less coming from other parts of the planet. “
The temperature reading of a planet is seen as a way to characterize its atmosphere.
“The planet is much colder than expected, indicating that it affects most of the starlight of the event, which is probably due to daytime clouds,” said Nicholas Cowan, co-author of the Research Institute for Exoplanets (IREX). McGill University of Montreal, who assisted in the analysis and interpretation of thermal phase curve measurements. “The planet does not transfer even more heat to its nocturnal space, but we think we understand that: the stars that are absorbed are probably absorbed into the atmosphere, from which the rays quickly turn into space.”
According to Crossfield, the result is only the first step in a new phase of exoplanetary exploration as the study of exoplanet atmospheres continues to move towards smaller and smaller planets.
This artist’s imprint LTT 9779B shows that it orbits a star. This transition briefly intercepts a complimentary fraction of the star’s light, and this is how the Earth was discovered by NASA’s Tess mission. Credit: Ethan Schmidt
“I would not say that we now understand everything about this planet, but we have measured enough to know that this will be a really fruitful object for future study.” “It is already targeted for accompanying observations James Webb Web Space Telescope, Which is NASA’s next large multibillion-dollar flagship space telescope moving forward in a few years. Our parameters that show us so far are what we call spectral absorption features – and its spectrum indicates carbon monoxide and / or carbon dioxide in the atmosphere. We are starting to get a handle on what molecules make of its atmosphere. Because we see this, and because of what this global temperature map looks like, it tells us something about how the wind revolves around energy and matter in the atmosphere of this mini-gas planet. “
Crossfield explained the extreme rarity of a Neptune-like world seen close to his host star, a planet devoid of astronomers calling it the “Hot Neptune Desert.”
“We think this is because the hot Neptune is not large enough to avoid atmospheric evaporation and mass damage.” “Therefore, most nearby hot exoplanets are either massive hot Jupiters or rocky planets that have lost most of their atmosphere.”
A companion letter to the research, led by Diana Dragomir, an assistant professor of physics and astronomy at the University of New Mexico, examines the exoplanet by means of secondary eclipse observations with hot Neptune’s Spitzer Infrared Array Camera (IRAC).
Although LTT 9779B is not suitable for colonization by human or any other known life forms, Crossfield said evaluating its environment would build technologies that could be used to find more welcome planets for life.
“If anyone believes what astronomers say about finding signs of life or oxygen on others, we have to show that we can really do it on simple materials,” he said. “In that sense, these big, hot planets like the LTT 9779B act like training wheels and show that we really know what we’re doing and can do everything right.”
Crossfield said his peek into such a strange and distant planetary atmosphere is also valuable on its own merits.
“As someone who studies this, we can do a lot of interesting planetary science in measuring the properties of these planets – just like people study the atmosphere. Jupiter, Sat. And Fri. – Even though we don’t think he will plan life, “he said. “It’s still interesting, and we can learn how these planets formed and a broader context of the planetary system.”
Crossfield said a lot of work remains to be done to better understand LTT 9779b and hot Neptunes that have not yet been discovered. (A companion paper on the atmospheric composition of the LTT 9779B is being published simultaneously with an analysis of its secondary eclipse “spectrum”, co-written by Crossfield.)
“We want to continue to observe it with other telescopes so that we can answer more questions.” “How can this planet maintain its atmosphere? How was it formed in the first place? Was it big at the beginning but lost a part of its original atmosphere? If so, why isn’t its atmosphere just a scaled version of the ultra-hot massive exoplanet’s atmosphere? And what else is hiding in its atmosphere? ”
Some co-authors of the KU researcher on paper also plan to continue the study of the impossible exoplanet.
“We have found carbon monoxide in its atmosphere. Permanent days are very hot, while very little heat is transferred to the night side,” said the University of IREX de Montreal. “Both findings tell LTT 9779B that with JWST there is a definite indication to make the planet a very interesting target for future detail characterization. We are now also planning more detailed phase curve observations with NIRISS on JWST.
