Using the Hobby-Eberly Telescope (HET) at McDonald Observatory at the University of Texas at Austin, a group of astronomers discovered some of the longest gas tails ever observed leaving a planet.
The planet, Cap P-32b, is almost two times the size of Jupiter and is losing its climate through sensational planes of helium spreading out before and behind it as it goes through space. The length of these tails exceeds 50 times the planet’s radius. Science Advances will publish the discovery on June 7.
The possibilities of getting away from material around planets are not incredible. They can be the consequence of a crash, liberating a path of residue and flotsam and jetsam. Or, they could be brought on by the atmosphere of a planet being blown into space by the heat of a nearby star, which would energize the planet. Hat-P-32b’s tail, on the other hand, is truly remarkable.
“Our discoveries about HAT-P-32b could help us understand how other planets and their stars interact. We can take high-precision measurements on hot Jupiters like this one and then apply what we learn to a broader variety of planets.”
Caroline Morley, assistant professor at The University of Texas at Austin.
Zhoujian Zhang, a NASA Sagan fellow at the University of California, Santa Cruz, stated, “It is exciting to see how gigantic the extended tails are compared to the size of the planet and its host star.” As a member of the University of Texas at Austin’s HET Exospheres Project, he was in charge of the team that made this discovery. The HET Exospheres Undertaking concentrates on the environments of planets beyond our planetary group.
Astronomers can observe a planet’s parent star as the planet passes in front of it in order to learn more about the atmosphere of planets outside our solar system. “Transit” is an expression for this. One model would be when Venus passes between the Earth and the sun.
If the planet has an atmosphere, the star shines light through it during a transit. Through a technique called “spectroscopy,” space experts can concentrate on this light to recognize what components are available in the air. Similar to white light shining through a prism, spectroscopy divides the light into a spectrum. Various groups of variety in the range compare to various components.
Past investigations had identified Cap P-32b’s tails. However, the true size of the tails remained unknown because astronomers had only observed the planet while it was passing in front of its star.
Caroline Morley, assistant professor at the University of Texas at Austin and principal investigator for the HET Exospheres Project, stated, “We would not have seen this without the long-timeframe observations that we can get with the Hobby-Eberly Telescope.” It enabled us to observe this planet throughout its entire orbit.”
Over the course of several nights, Zhang’s team observed HAT-P-32b, recording both the moment the planet crossed in front of the star and subsequent observations. This covered the planet’s entire orbit around its star, revealing its tails to their fullest extent.
The planet’s atmosphere was likely boiled off by the parent star, which is why HAT-P-32b has tails. Astronomers refer to the planet as a “hot Jupiter,” meaning that it is large, hot, gassy, and close to its star. Because of the tightness of its orbit, HAT-P-32b’s atmosphere’s gas is expanding as a result of the heat from its parent star. The environment has extended so much that some of it has gotten away from the planet’s gravitational force and been brought into space around the nearby star.
Morley stated, “Our findings on HAT-P-32b may assist us in comprehending how other planets and their stars interact.” We are able to apply our findings to a wider variety of planets after taking precise measurements on hot Jupiters like this one.”
The Hobby-Eberly Telescope (HET) and the study of planets’ atmospheres The HET is particularly well-suited for studying planets outside our solar system’s atmosphere. Its high-goal instrument, the Livable Zone Planet Locater spectrograph, can detect objects at close infrared frequencies. Astronomers can observe the gas escaping from HAT-P-32b and other similar planets thanks to this, which includes the wavelength associated with helium.
The fact that HET observes the same area of the sky every night is another advantage. The HET telescope’s 10-by-11-meter mirror is always tilted at 55 degrees above the horizon, in contrast to the majority of other telescopes, which tilt up and down. High-precision, long-term observations of the same sky area every night can be made as a result of this.
Zhang stated, “We can detect physically large structures such as this one because we can observe the system every night for several days in a row.” Different planets could likewise have stretched out, getting away from the air, ready to be found through comparative observing.”
More information: Zhoujian Zhang et al, Giant tidal tails of helium escaping the hot Jupiter HAT-P-32 b, Science Advances (2023). DOI: 10.1126/sciadv.adf8736
