NASA scientists report the discovery of LHS 475 b, an exoplanet almost identical in size and mass to Earth, and the first to be confirmed by the James Webb Space Telescope.
LHS 475 is a red dwarf star with about a quarter of our Sun’s mass and radius, located relatively close in our stellar neighbourhood at 41 light years away. Astronomers have now confirmed that the system contains at least one known exoplanet, designated LHS 475 b.
A recently discovered acoustic effect allows a hot gas to simulate the gravity-induced convection within a star or giant planet.
Sometimes a light bulb goes on—literally—and a scientific advance is made. Researchers studying an acoustic effect in high-powered light bulbs have developed a system that mimics the gravitational field around planets and stars [1]. The team demonstrated that sound waves in the bulb generate a force that pulls gas toward the bulb’s center. This gravity-like force causes the gas to move around in convection cycles that resemble fluid flows in the Sun and in giant planets. With further improvements, the system could be used to investigate convection behavior that is too difficult to simulate with computers.
In 2017, research on high-powered sulfur lamps revealed that sound waves could drive hot gas to ball up in the center of the bulbs [2]. The surprising phenomenon caught the attention of Seth Putterman’s acoustic group at the University of California, Los Angeles. The team studied the clumping and showed that it could be explained by the acoustic radiation force. This force is well known in acoustic levitation experiments, in which sound waves scattering off an object, such as a small bead, can exert a force (see Synopsis: Tossing and Turning). Putterman and his colleagues showed that, in the bulbs, this force acts not at the surface of an object where sound scatters, but throughout the gas, where density variations redirect the sound waves. “We knew that the force acts at a sharp interface between something solid and a gas,” says team member John Koulakis. “In the bulb, there’s no sharp interface—just variations—but there still is a force.”
Two astronauts from the International Space Station (ISS) yesterday performed the first spacewalk of the year, working on the exterior of the station as part of a long-term program to upgrade the ISS power system. The spacewalk took place on Friday, January 20, and lasted over seven hours, though one troublesome strut wasn’t bolted into place as planned.
The two astronauts performing the spacewalk were NASA astronaut Nicole Mann and Japan Aerospace Exploration Agency (JAXA) astronaut Koichi Wakata, and this was the first spacewalk for each of them.
The ISS solar arrays which provide power to the station are getting old, so in a long-term project astronauts are installing new arrays called iROSAs at an offset on top of the old arrays — allowing both sets of arrays to provide power. The aim of the spacewalk yesterday was to install two mounting platforms, which would be used to install new solar arrays later this year.
It’s not at every university that laser pulses powerful enough to burn paper and skin are sent blazing down a hallway. But that’s what happened in UMD’s Energy Research Facility, an unremarkable looking building on the northeast corner of campus. If you visit the utilitarian white and gray hall now, it seems like any other university hall—as long as you don’t peak behind a cork board and spot the metal plate covering a hole in the wall.
But for a handful of nights in 2021, UMD Physics Professor Howard Milchberg and his colleagues transformed the hallway into a laboratory: The shiny surfaces of the doors and a water fountain were covered to avoid potentially blinding reflections; connecting hallways were blocked off with signs, caution tape and special laser-absorbing black curtains; and scientific equipment and cables inhabited normally open walking space.
As members of the team went about their work, a snapping sound warned of the dangerously powerful path the laser blazed down the hall. Sometimes the beam’s journey ended at a white ceramic block, filling the air with louder pops and a metallic tang. Each night, a researcher sat alone at a computer in the adjacent lab with a walkie-talkie and performed requested adjustments to the laser.
This “may be the first direct detection of a ‘Gaia exoplanet.’”
The European Space Agency’s (ESA’s) Gaia spacecraft helped capture an exoplanet, paving the way for follow-up observations that revealed the distant planet had a nuclear fusion reaction in its core.
“The discovery of HD 206,893 c is a really important moment for the study of exoplanets, as ours may be the first direct detection of a ‘Gaia exoplanet,’” Professor Sasha Hinkley at the University of Exeter in England explained in a press statement.
ESA / ATG
Jan. 20 (UPI) — Two astronauts embarked on the first spacewalk of 2023 on Friday as they work toward upgrading the International Space Station’s power generation system.
NASA astronaut Nicole Mann teamed up with Koichi Wakata of the Japan Aerospace Exploration Agency for the morning spacewalk, expected to last about 6 1/2 hours. They will install a modification kit at the far end of the ISS, allowing for the future installation of the roll-out solar array.
The spacewalk was scheduled to start at 8:15 a.m., EST, but NASA officials said the operation was ahead of schedule with both astronauts setting their spacesuits to battery power about a minute earlier, marking the official start of the mission.
When it comes to star formation in interstellar clouds of gas and dust, there’s an ongoing tug-of-war between two cloud-shaping processes. Young, massive stars inject energy into their surroundings in a way that both disrupts star formation by shredding the surrounding medium and encourages it by collecting dense gas shells that are prone to gravitational collapse. Which of these feedback processes dominates has been unclear, but new observations by Lars Bonne of NASA’s Ames Research Center and his colleagues suggest that stellar feedback significantly suppresses star formation. These findings—presented earlier this month at the 241st Meeting of the American Astronomy Society in Seattle—provide a missing piece in understanding why proposed rapid star-formation rates have long misaligned with observations.
Recent observations suggest that the formation of high-mass stars—ones greater than 8 times the mass of the Sun—is associated with the gravitational collapse of the surrounding cloud of molecular gas. This collapse leads to a high concentration of material, which should induce further star formation. However, the expected high star-formation rates are not observed, with typically only a few percent of the molecular cloud’s mass becoming new stars. “If stellar feedback indeed disperses the collapsing molecular cloud on the same timescale that new stars form, it could prevent these proposed high star-formation rates,” Bonne says. But predicting the impact and role of stellar feedback on the surrounding molecular cloud remains extremely difficult.
Now with data from NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA, now retired) and the Chandra X-ray Observatory, Bonne and his colleagues have tracked the process in real time. The first observation target was a star-forming complex called RCW 36, which is several light-years across and is located 2,900 light-years away in a molecular cloud within the constellation Vela. Like other star-forming complexes, RCW 36 consists of a large region of ionized atomic hydrogen (HII, pronounced “H-two”). This region includes a cluster of young stars and two low-density cavities that extend outward in opposite directions. A ring of gas forms a waist between the two cavities, resulting in an hourglass-like shape.
A recent model suggests that passing interstellar objects should get pulled into our Sun’s orbit fairly often.
NOIRLab.
The image, taken by the Dark Energy Camera (DECam) on the NSF’s NOIRLab’s Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile, is viewable online. Anyone can zoom in on the ten terabytes of data made up of 21,400 individual exposures.
A group of astronomers has snapped what is described as the most detailed image of the Moon ever snapped from the surface of Earth.
