The James Webb Space Telescope (JWST) has provided new clues about how the ultra-hot exoplanet WASP-121b was formed and where it might have originated in the disc of gas and dust around its star. The detection of multiple key molecules, including water vapour, carbon monoxide, silicon monoxide, and methane, has allowed a team of astronomers to compile an inventory of the carbon, oxygen, and silicon in the atmosphere of WASP-121b.

The ultra-hot giant planet orbits its host star at a distance only about twice the star’s diameter, completing one orbit in approximately 30.5 hours. The planet exhibits two distinct hemispheres: one that always faces the host star, with temperatures locally exceeding 3000 degrees Celsius, and an eternal nightside where temperatures drop to 1500 degrees.

The team led by astronomers Thomas Evans-Soma and Cyril Gapp was able to compile an inventory of the carbon, oxygen, and silicon in the atmosphere of WASP-121b. The detection of these molecules suggests that the planet’s atmosphere is rich in gases that are stable at high temperatures.

However, the team’s observations also revealed a surprise: the abundance of methane on the nightside of the exoplanet was much higher than expected. To explain this result, the team proposes that methane gas must be rapidly replenished on the nightside to maintain its high abundance. A plausible mechanism for doing this involves strong vertical currents lifting methane gas from lower atmospheric layers.

The JWST’s Near-Infrared Spectrograph (NIRSpec) was used to observe WASP-121b throughout its complete orbit around its host star. As the planet rotates on its axis, the heat radiation received from its surface varies, exposing different portions of its irradiated atmosphere to the telescope. This allowed the team to characterize the conditions and chemical composition of the planet’s dayside and nightside.

The astronomers also captured observations as the planet transited in front of its star. During this phase, some starlight filters through the planet’s atmospheric limb, leaving spectral fingerprints that reveal its chemical makeup. The emerging transmission spectrum confirmed the detections of silicon monoxide, carbon monoxide, and water that were made with the emission data.

The MPIA scientists involved in this study included Thomas M. Evans-Soma (also at the University of Newcastle, Australia), Cyril Gapp (also at Heidelberg University), Eva-Maria Ahrer, Duncan A. Christie, Djemma Ruseva (also at the University of St Andrews, UK), and Laura Kreidberg.

Other researchers included David K. Sing (Johns Hopkins University, Baltimore, USA), Joanna K. Barstow (The Open University, Milton Keynes, UK), Anjali A. A. Piette (University of Birmingham, UK and Carnegie Institution for Science, Washington, USA), Jake Taylor (University of Oxford, UK), Joshua D. Lothringer (Space Telescope Science Institute, Baltimore, USA and Utah Valley University, Orem, USA), and Jayesh M. Goyal (National Institute of Science Education and Research (NISER), Odisha, India).

The JWST’s role in the discovery was crucial, as it allowed the team to observe WASP-121b throughout its complete orbit around its host star, capturing a wealth of information about the exoplanet’s atmosphere and composition.

In conclusion, the study provides new insights into the formation and evolution of ultra-hot exoplanets like WASP-121b. The detection of methane on the nightside of the exoplanet challenges current dynamical models of exoplanetary atmospheres, suggesting that these models will need to be adapted to reproduce the strong vertical mixing observed in this study.

The world of black holes has long been divided into three categories: stellar-mass black holes (about five to 50 times the mass of the sun), supermassive black holes (millions to billions of times the mass of the sun), and intermediate-mass black holes with masses somewhere in between. While we know that intermediate-mass black holes should exist, little is known about their origins or characteristics – they are considered the rare “missing links” in black hole evolution.

However, four new studies have shed new light on this mystery. The research was led by a team in the lab of Assistant Professor Karan Jani, who also serves as the founding director of the Vanderbilt Lunar Labs Initiative. The work was funded by the National Science Foundation and the Vanderbilt Office of the Vice Provost for Research and Innovation.

The primary paper, “Properties of ‘Lite’ Intermediate-Mass Black Hole Candidates in LIGO-Virgo’s Third Observing Run,” was published in Astrophysical Journal Letters and led by Lunar Labs postdoctoral fellow Anjali Yelikar and astrophysics Ph.D. candidate Krystal Ruiz-Rocha. The team reanalyzed data from the Nobel-Prize winning Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors in the U.S. and the Virgo detector in Italy.

The researchers found that these waves corresponded to mergers of black holes greater than 100 to 300 times the mass of the sun, making them the heaviest gravitational-wave events recorded in astronomy. “Black holes are the ultimate cosmic fossils,” Jani said. “The masses of black holes reported in this new analysis have remained highly speculative in astronomy. This new population of black holes opens an unprecedented window into the very first stars that lit up our universe.”

Earth-based detectors like LIGO capture only a split second of the final collision of these “lightweight” intermediate-mass black holes, making it challenging to determine how the universe creates them. To tackle this, Jani’s lab turned to the upcoming European Space Agency and NASA’s Laser Interferometer Space Antenna (LISA) mission, launching in the late 2030s.

In two additional studies published in Astrophysical Journal, “A Sea of Black Holes: Characterizing the LISA Signature for Stellar-origin Black Hole Binaries,” led by Ruiz-Rocha, and “A Tale of Two Black Holes: Multiband Gravitational-wave Measurement of Recoil Kicks,” led by former summer research intern Shobhit Ranjan, the team showed LISA can track these black holes years before they merge, shedding light on their origin, evolution, and fate.

Detecting gravitational waves from black hole collisions requires extreme precision – like trying to hear a pin drop during a hurricane. In a fourth study also published in Astrophysical Journal, “No Glitch in the Matrix: Robust Reconstruction of Gravitational Wave Signals under Noise Artifacts,” the team showcased how artificial intelligence models guarantee that signals from these black holes remain uncorrupted from environmental and detector noise in the data. The paper was led by postdoctoral fellow Chayan Chatterjee and expands upon Jani’s AI for New Messengers Program, a collaboration with the Data Science Institute.

“We hope this research strengthens the case for intermediate-mass black holes as the most exciting source across the network of gravitational-wave detectors from Earth to space,” Ruiz-Rocha said. “Each new detection brings us closer to understanding the origin of these black holes and why they fall into this mysterious mass range.”

Moving forward, Yelikar said the team will explore how intermediate-mass black holes could be observed using detectors on the moon.

“Access to lower gravitational-wave frequencies from the lunar surface could allow us to identify the environments these black holes live in – something Earth-based detectors simply can’t resolve,” she said.

In addition to continuing this research, Jani will also be working with the National Academies of Sciences, Engineering, and Medicine on a NASA-sponsored study to identify high-value lunar destinations for human exploration to address decadal-level science objectives. As part of his participation in this study, Jani will be contributing to the Panel on Heliophysics, Physics, and Physical Science, to identify and articulate the science objectives related to solar physics, space weather, astronomy, and fundamental physics that would be most enabled by human explorers on the moon.

“This is an exciting moment in history – not just to study black holes, but to bring scientific frontiers together with the new opportunity of training the next generation of students whose discoveries will be shaped by, and made from, the moon,” Jani said.

The discovery of an object called ASKAP J1832-0911 has left astronomers puzzled. This mysterious entity emits pulses of radio waves and X-rays for two minutes every 44 minutes. What makes this finding even more intriguing is that it’s the first time such an object, known as a long-period transient (LPT), has been detected in X-rays.

The team behind this discovery used the ASKAP radio telescope to detect the radio signals, which they then correlated with X-ray pulses detected by NASA’s Chandra X-ray Observatory. This coincidence of observations allowed them to confirm that ASKAP J1832-0911 is indeed emitting both types of radiation.

LPTs are a relatively recent discovery, with only ten such objects found so far. Scientists still have no clear explanation for what causes these signals or why they ‘switch on’ and ‘switch off’ at such long, regular intervals. Some theories suggest that ASKAP J1832-0911 could be a magnetar or a pair of stars in a binary system with one star being a highly magnetised white dwarf.

However, even these theories don’t fully explain what’s being observed. This discovery might indicate the existence of new types of physics or models of stellar evolution. By detecting objects like ASKAP J1832-0911 using both X-rays and radio waves, scientists hope to find more examples and gain a better understanding of their nature.

The discovery of ASKAP J1832-0911 is not only significant for the scientific community but also showcases an incredible teamwork effort between researchers across the globe. The study’s findings have been published in Nature, and the object itself is located in our Milky Way galaxy about 15,000 light-years from Earth.