It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Monday, February 05, 2024
SPACE
A Russian cosmonaut sets a new record for the most time in space
by The Associated Press
From left: CSA astronaut David Saint Jacques, Russian cosmonaut Оleg Kononenko and U.S. astronaut Anne McClain pose for a photo before their final preflight practical examination in a mock-up of a Soyuz space craft at Russian Space Training Center in Star City, outside Moscow, Russia, Wednesday, Nov. 14, 2018. The Russian space agency says one of its cosmonauts has broken the world record for the most time spent in space. Oleg Kononenko, who's 59 has made five journeys to the International Space Station, dating back to 2008.
Credit: AP Photo/Pavel Golovkin, File
Russian cosmonaut Oleg Kononenko has broken the world record for the most cumulative time spent in space, Russia's space agency Roscosmos reported Sunday.
The 59-year-old has now spent more than 878 days and 12 hours in space, surpassing fellow Russian Gennady Padalka, who set the previous record of 878 days, 11 hours, 29 minutes, and 48 seconds in 2015.
Kononenko has made five journeys to the International Space Station, dating back to 2008.
Speaking with Russian state news agency TASS, the engineer said that each trip to the ISS required careful preparation due to the station's constant upgrades—but that life as a cosmonaut was a childhood dream come true.
"I fly into space to do what I love, not to set records. I've dreamt of and aspired to become a cosmonaut since I was a child. That interest—the opportunity to fly into space, to live and work in orbit—motivates me to continue flying," he told TASS.
Kononenko's current trip to the ISS began on Sept. 15, 2023, when he launched alongside NASA astronaut Loral O'Hara and Roscosmos compatriot Nikolai Chub. By the end of this expedition, the cosmonaut is expected to become the first person to accumulate 1,000 days in space.
The International Space Station is one of the few areas in which the United States and Russia still cooperate closely following Moscow's invasion of Ukraine in Feb. 2022. Roscosmos announced in December that its cross-flight program with NASA transporting astronauts to the ISS had been extended until 2025.
Russian Space Agency experts test a space suit of Russian cosmonaut Oleg Kononenko, a crew member of the next mission to the International Space Station, prior to the launch of Soyuz-FG booster rocket with the space capsule Soyuz TMA-14M at the Russian leased Baikonur Cosmodrome, in Kazakhstan, Wednesday, July 22, 2015. The Russian space agency says one of its cosmonauts has broken the world record for the most time spent in space. Oleg Kononenko, who's 59 has made five journeys to the International Space Station, dating back to 2008. Credit: AP Photo/Pavel Golovkin, File
FILE -- Russian cosmonaut Oleg Kononenko, a crew member of the next mission to the International Space Station, attends a news conference at the Russian leased Baikonur Cosmodrome, in Kazakhstan, Tuesday, July 21, 2015. The Russian space agency says one of its cosmonauts has broken the world record for the most time spent in space. Oleg Kononenko, who's 59 has made five journeys to the International Space Station, dating back to 2008. Credit: AP Photo/Pavel Golovkin, File
A color-composite image of PEARLSDG made with JWST NIRCAM data. Individual stars are visible as small points of light in the image. Its somewhat dull color and lack of many bright stars is consistent with its old age and lack of ongoing star formation. Credit: NASA, ESA, CSA, Jake Summers (ASU), Jordan C. J. D'Silva (UWA), Anton M. Koekemoer (STScI), Aaron Robotham (UWA) and Rogier Windhorst (ASU)
A team of astronomers, led by Arizona State University Assistant Research Scientist Tim Carleton, has discovered a dwarf galaxy that appeared in James Webb Space Telescope imaging that wasn't the primary observation target.
Galaxies are bound together by gravity and made up of stars and planets, with vast clouds of dust and gas as well as dark matter. Dwarf galaxies are the most abundant galaxies in the universe, and are by definition small with low luminosity. They have fewer than 100 million stars, while the Milky Way, for example, has nearly 200 billion stars.
Recent dwarf galaxy observations of the abundance of "ultra-diffuse galaxies" beyond the reach of previous large spectroscopic surveys suggest that our understanding of the dwarf galaxy population may be incomplete.
In a newly published study, Carleton and the team were initially looking at a cluster of galaxies as part of the JWST Prime Extragalactic Areas for Reionization and Lensing Science (PEARLS) project.
The dwarf galaxy, PEARLSDG, happened to appear in some of the team's JWST imaging. It wasn't the target at all—just a bit off from the main observation field, in the area of space where they weren't expecting to see anything.
Their results have been published in the Astrophysical Journal Letters.
PEARLSDG did not have the usual characteristics of a dwarf galaxy one would expect to see. It isn't interacting with a nearby galaxy, but it also isn't forming new stars. As it turns out, it is an interesting case of an isolated quiescent galaxy.
"These types of isolated quiescent dwarf galaxies haven't really been seen before except for relatively few cases. They are not really expected to exist given our current understanding of galaxy evolution, so the fact that we see this object helps us improve our theories for galaxy formation," said Carleton. "Generally, dwarf galaxies that are out there by themselves are continuing to form new stars."
Until now, astronomers' understanding of galaxy evolution showed an isolated galaxy that continued to form young stars or it would interact with a more massive companion galaxy. This theory didn't apply to PEARLSDG, which presents as an old stellar population, not forming new stars as well as keeping to itself.
In a further surprise, individual stars can be observed in the team's JWST images. These stars are brighter in JWST wavelengths; it is one of the farthest galaxies that we can see these stars with this level of detail. The brightness of these stars allows astronomers to be able to measure its distance—98 million light-years.
Top: the JWST of the PEARLSDG galaxy (blue = F090W + F150W, green = F200W + 0.5 × F277W, red = 0.5 × F277W+F356W+F444W). Bottom: DECALS grz image of the sky immediately surrounding PEARLSDG. Both images are aligned such that north is up and east is left. PEARLSDG is identified with the cyan box, and the green squares show the area covered by NIRCam imaging. Also shown are two of the closest (in-projection) nearby massive galaxies (identified in red circles). Credit: The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad1b56
For this study, Carleton—who is an assistant research scientist at the Beus Center for Cosmic Foundations in the School of Earth and Space Exploration at ASU—and the team used a wide range of data.
This includes imaging data from JWST's Near-InfraRed Camera (NIRCam); spectroscopic data from the DeVeney Optical Spectrograph on the Lowell Discovery Telescope in Flagstaff, Arizona; archival imaging from NASA's Galex and Spitzer space telescopes; and ground-based imaging from the Sloan Digital Sky Survey and the Dark Energy Camera Legacy Survey.
JWST's NIRCam has very high angular resolution and sensitivity, allowing the team to identify individual stars in this distant galaxy. Just like individual cells coming into focus under a microscope, these observations brought the components of PEARLSDG into sharp focus.
Importantly, identifying specific stars in the imaging provided a key clue to its distance—these stars have a specific intrinsic brightness, so by measuring their apparent brightness with JWST, the team was able to determine how far away they are. It turns out that these stars were some of the most distant stars of their type to be observed.
All of the archival imaging data, observed at ultraviolet, optical and infrared wavelengths, was pulled together to study the color of PEARLSDG. Newly formed stars have a specific color signature, so the absence of such a signature was used to show that PEARLSDG was not forming new stars.
The DeVeney Spectrograph at the Lowell Discovery Telescope spreads the light astronomical objects into its distinct components, allowing astronomers to study its properties in detail. For example, the specific wavelength shift observed in features in the spectroscopic data encodes information about the motion of PEARLSDG, using the same Doppler effect that radar guns use to measure the speed of drivers on Arizona roads.
This was key to show that PEARLSDG is not associated with any other galaxy and is truly isolated.
Additionally, particular features in the spectrum are sensitive to the presence of young stars, so the absence of those features further corroborated the measurements of the absence of young stars from the imaging data.
"This was absolutely against people's expectations for a dwarf galaxy like this," Carleton said.
This discovery changes astronomers' understanding of how galaxies form and evolve. It suggests the possibility that many isolated quiescent galaxies are waiting to be identified and that JWST has the tools to do so.
More information: Timothy Carleton et al, PEARLS: A Potentially Isolated Quiescent Dwarf Galaxy with a Tip of the Red Giant Branch Distance of 30 Mpc, The Astrophysical Journal Letters (2024). DOI: 10.3847/2041-8213/ad1b56
Planets can gravitationally affect each other when their orbits line up. Credit: NASA/JPL-Caltech
Planets orbit their parent stars while separated by enormous distances—in our solar system, planets are like grains of sand in a region the size of a football field. The time that planets take to orbit their suns have no specific relationship to each other.
But sometimes, their orbits display striking patterns. For example, astronomers studying six planets orbiting a star 100 light years away have just found that they orbit their star with an almost rhythmic beat, in perfect synchrony. Each pair of planets completes their orbits in times that are the ratios of whole numbers, allowing the planets to align and exert a gravitational push and pull on the other during their orbit.
This type of gravitational alignment is called orbital resonance, and it's like a harmony between distant planets.
Greek mathematician Pythagoras discovered the principles of musical harmony 2,500 years ago by analyzing the sounds of blacksmiths' hammers and plucked strings.
He believed mathematics was at the heart of the natural world and proposed that the sun, moon and planets each emit unique hums based on their orbital properties. He thought this "music of the spheres" would be imperceptible to the human ear.
VIDEO Orbital resonance, as seen with Jupiter’s moons, happens when planetary bodies’ orbits line up – for example, Io orbits Jupiter four times in the time it takes Europa to orbit twice and Ganymede to orbit once.Credit: WolfmanSF/Wikimedia Commons
Four hundred years ago, Johannes Kepler picked up this idea. He proposed that musical intervals and harmonies described the motions of the six known planets at the time.
To Kepler, the solar system had two basses, Jupiter and Saturn; a tenor, Mars; two altos, Venus and Earth; and a soprano, Mercury. These roles reflected how long it took each planet to orbit the sun, lower speeds for the outer planets and higher speeds for the inner planets.
He called the book he wrote on these mathematical relationships "The Harmony of the World." While these ideas have some similarities to the concept of orbital resonance, planets don't actually make sounds, since sound can't travel through the vacuum of space.
Orbital resonance
Resonance happens when planets or moons have orbital periods that are ratios of whole numbers. The orbital period is the time taken for a planet to make one complete circuit of the star. So, for example, two planets orbiting a star would be in a 2:1 resonance when one planet takes twice as long as the other to orbit the star. Resonance is seen in only 5% of planetary systems.
In the solar system, Neptune and Pluto are in a 3:2 resonance. There's also a triple resonance, 4:2:1, among Jupiter's three moons: Ganymede, Europa and Io. In the time it takes Ganymede to orbit Jupiter, Europa orbits twice and Io orbits four times. Resonances occur naturally, when planets happen to have orbital periods that are the ratio of whole numbers.
Musical intervals describe the relationship between two musical notes. In the musical analogy, important musical intervals based on ratios of frequencies are the fourth, 4:3, the fifth, 3:2, and the octave, 2:1. Anyone who plays the guitar or the piano might recognize these intervals.
Musical intervals can be used to create scales and harmony.
Orbital resonances can change how gravity influences two bodies, causing them to speed up, slow down, stabilize on their orbital path and sometimes have their orbits disrupted.
Think of pushing a child on a swing. A planet and a swing both have a natural frequency. Give the child a push that matches the swing motion and they'll get a boost. They'll also get a boost if you push them every other time they're in that position, or every third time. But push them at random times, sometimes with the motion of the swing and sometimes against, and they get no boost.
For planets, the boost can keep them continuing on their orbital paths, but it's much more likely to disrupt their orbits.
Exoplanet resonance
Exoplanets, or planets outside the solar system, show striking examples of resonance, not just between two objects but also between resonant "chains" involving three or more objects.
Orbital resonance can cause planets or asteroids to speed up or start to wobble.
The star Gliese 876 has three planets with orbit period ratios of 4:2:1, just like Jupiter's three moons. Kepler 223 has four planets with ratios of 8:6:4:3.
The red dwarf Kepler 80 has five planets with ratios of 9:6:4:3:2, and TOI 178 has six planets, of which five are in a resonant chain with ratios of 18:9:6:4:3.
TRAPPIST-1 is the record holder. It has seven Earth-like planets, two of which might be habitable, with orbit ratios of 24:15:9:6:4:3:2.
The newest example of a resonant chain is the HD 110067 system. It's about 100 light years away and has six sub-Neptune planets, a common type of exoplanet, with orbit ratios of 54:36:24:16:12:9. The discovery is interesting because most resonance chains are unstable and disappear over time.
Despite these examples, resonant chains are rare, and only 1% of all planetary systems display them. Astronomers think that planets form in resonance, but small gravitational nudges from passing stars and wandering planets erase the resonance over time. With HD 110067, the resonant chain has survived for billions of years, offering a rare and pristine view of the system as it was when it formed.
Orbit sonification
Music from planetary orbits, created by astronomers at the European Southern Observatory.
With exoplanets, sonification can convey the mathematical relationships of their orbits. Astronomers at the European Southern Observatory created what they call "music of the spheres" for the TOI 178 system by associating a sound on a pentatonic scale to each of the five planets.
A similar musical translation has been done for the TRAPPIST-1 system, with the orbital frequencies scaled up by a factor of 212 million to bring them into audible range.
Astronomers have also created a sonification for the HD 110067 system. People may not agree on whether these renditions sound like actual music, but it's inspiring to see Pythagoras' ideas realized after 2,500 years.
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