WEBB MAPS LARGE WATER JET FROM SATURN'S MOON ENCELADUS
ESA
The James Webb Telescope recently captured a water jet erupting from the surface of Enceladus, one of Saturn's many moons. Enceladus is a small moon, with an icy crust and a saline, liquid water ocean underneath it. Beneath the liquid ocean is the moon's rocky core. Enceladus is one of the most promising places in the Solar System to search for life beyond Earth.
Among the moon's unique features are the geyser-like volcanic eruptions that eject ice particles, water vapour and organic chemicals into space. JWST observed one such event which produced a particularly large plume. The plume was more than 9,600 kilometres long and the water vapour expelled into space did so at an impressive rate of 300 litres per second.
The NASA/ESA/ASI Cassini mission was the first to capture the plumes of the Saturnian moon. It also flew through them in order to sample what they were made of. Now, Webb's Integral Field Unit aboard the NIRSpec (Near Infrared Spectrograph) Instrument, is offering a different perspective.
The instrument's observations have shown that the water vapour plumes from Enceladus feed a Saturnian feature known as the torus. Located at the same place as the E-ring, the torus is made of water. Astronomers have used James Webb Telescope data to determine that about 30% of the water from the plumes remains in the torus while the other 70% escapes and enriches the rest of the Saturn system with water.
This research is one of many steps towards looking for biological signatures in the icy moons of Jupiter and Saturn.
AN X-RAY LOOK AT THE HEART OF POWERFUL QUASARS
RAS
Quasars are some of the brightest and most distant objects in the known Universe. They are powered by gas falling into the supermassive black hole found in their centre. One such quasar is the SMSS J114447.77-430859.3, or J1144 for short. Known as the most luminous quasar in the last 9 billion years of the Universe's history, this time the researchers' focus was on the object's X-ray emission.
The quasar is 9.6 billion light years away from the Earth and is 100,000 times brighter than the Sun. Compared to other known quasars, J1144 is closer to us. This presents astronomers with a unique opportunity to better understand the black hole that powers the quasar and its surrounding environment.
Work done by Dr Elias Kammoun and Zsofi Igo, (PhD candidate) used data provided by the SkyMapper Southern Survey (SMSS). SMSS combines data from four different observatories: the eROSITA instrument aboard the Spectrum-Roentgen-Gamma (SRG) observatory, the XMM-Newton observatory (ESA), NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) and the Neil Gehrels Swift observatory (NASA).
The researchers used the data from the above instruments to measure the temperature of the X-rays emitted by J1144. The temperature of the X-rays is an astounding 350 million Kelvin, more than 60,000 times the temperature at the surface of the Sun. The same data also revealed that the mass of the black hole at the heart of the quasar is 10 billion solar masses.
The X-ray light from the quasar, varied on a timescale of a few days, which is unusual for such objects. Typically, X-ray light from quasars varies on a timescale of months to years. The research also revealed that some of the gas falls into the black hole but a portion of it is ejected as powerful winds and deposits large amounts of energy into the host galaxy. Monitoring this quasar will start in June, in order to better understand the black hole at its centre and its interactions with its direct surrounding environment and also its interactions with its host galaxy.
PLANETARY BODIES DISCOVERED IN HABITABLE ZONE OF DEAD STAR
RAS
White dwarfs are stars at the final phase of their life, where they have undergone their giant phase, shed their outer layers of material and hydrogen in their core has been depleted. What is left behind is their hot core, which will slowly cool down for over billions of years. Therefore, it is rather surprising to have discovered planetary bodies orbiting one such white dwarf star in the star's habitable zone.
The white dwarf in question is called WD1054–226, a white dwarf 117 light years away. The star was observed over the course of 18 nights with the ULTRACAM high-speed camera on the ESO 3.5m New Technology Telescope (NTT) at the La Silla Observatory in Chile. Additional data from the NASA Transiting Exoplanet Survey Satellite (TESS) showed dips in light corresponding to 65 evenly spaced clouds of planetary debris orbiting the star every 25 hours. One of the conclusions drawn was that the regularity of the transiting structures suggests they are kept in such a precise arrangement by a nearby planet. This planet is thought to be roughly the same size as the rocky planets in our Solar System. The planet is about 2.5 million kilometres away from its host star.
Since the star has already undergone its giant phase, it is unlikely that the planetary structures are the same ones that formed along with the star in the beginning of its life. Instead they have to have been formed recently or arrived there after the red giant phase by some other mechanism.
Lead author of the study, Professor Jay Farihi highlighted that this is the first time that astronomers have observed planetary bodies in the habitable zone of a white dwarf. He also said that the regularity of these bodies' orbits could be explained if there was a major planet nearby. However, more evidence is needed to confirm the presence of such a planet. Studying such systems offers a glimpse into our own solar system's future given that our Sun will enter its white dwarf phase in a few billion years too.
ASTRONOMERS DISCOVER LAST PLANETS SEEN BY KEPLER SPACE TELESCOPE
RAS
Astronomers at the Massachusetts Institute of Technology and the University of Wisconsin at Madison, with the help of citizen scientists, have discovered the last three planets that the Kepler Space Telescope gazed upon before going dark. The research is published in Monthly Notices of the Royal Astronomical Society.
More than 5,000 planets are confirmed to exist beyond our solar system. Over half were discovered by NASA’s Kepler Space Telescope. Over nine and a half years, the spacecraft trailed the Earth, scanning the skies for periodic dips in starlight that could signal the presence of a planet crossing in front of its host star. In its last days, the telescope kept recording the brightness of stars as it was running out of fuel. On 30 October 2018, its fuel tanks depleted, and the spacecraft was officially retired.
The team of astronomers, led by Professor Andrew Vanderburg and Elyse Incha, combed through the telescope’s last week of high-quality data and spotted three stars, in the same part of the sky, that appeared to dim briefly. The scientists determined that two of the stars each host a planet, while the third hosts a planet “candidate” that has yet to be verified.
The two validated planets are K2-416 b, a planet that is about 2.6 times the size of the Earth and that orbits its star about every 13 days, and K2-417 b, a slightly larger planet that is just over three times Earth’s size and that circles its star every 6.5 days. For their size and proximity to their stars, both planets are considered “hot mini-Neptunes.” They are located about 400 light years from Earth.
The planet candidate is EPIC 246251988 b — the largest of the three at almost four times the size of the Earth. This Neptune-sized candidate orbits its star in around 10 days, and is slightly farther away, 1,200 light years from Earth. Vanderburg and Incha presented the challenge to the Visual Survey Group, a team of amateur and professional astronomers who hunt for exoplanets in satellite data. They search by eye through thousands of recorded light curves of each star, looking for characteristic dips in brightness that signal a “transit,” or the possible crossing of a planet in front of its star.
The astronomers spent a few days efficiently looking through the light curves that Kepler recorded from about 33,000 stars. The team worked with only a week’s worth of high-quality data from the telescope before it began to lose fuel and focus. Even in this short window of data, the team was able to spot a single transit in three different stars. Incha and Vanderburg then looked at the telescope’s very last, lower-quality observations, taken in its last 11 days of operation, to see if they could spot any additional transits in the same three stars — evidence that a planet was periodically circling its star.
This search revealed a second transit for K2-416 b and K2-417 b , validating that they each host a planet. The team also detected a similar dip in brightness for K2-417 b in data taken of the same star by NASA’s Transiting Exoplanet Survey Satellite (TESS), a mission that is led and operated by MIT. The data from TESS helped to confirm the planet candidate around this star.
“We have found what are probably the last planets ever discovered by Kepler, in data taken while the spacecraft was literally running on fumes,” says Professor Vanderburg. “The planets themselves are not particularly unusual, but their atypical discovery and historical importance makes them interesting.”
“Those two are pretty much without a doubt planets,” Incha says. “We also followed up with ground-based observations to rule out all kinds of false positive scenarios for them, including background star interference, and close-in stellar binaries.”
“These are the last chronologically observed planets by Kepler, but every bit of the telescope’s data is incredibly useful,” Incha says. “We want to make sure none of that data goes to waste, because there are still a lot of discoveries to be made.”
FLYING FRYING IN MICROGRAVITY
ESA
ESA has been supporting research in frying cooking methods in microgravity to fill in knowledge gaps on Earth and in space. Even though frying potatoes is done everywhere around the world, it involves complex physics and chemistry, and in space everything becomes more complicated. It was no sure thing that frying would work without gravity. Without buoyancy pulling upwards, bubbles might stick to the surface of a potato, shielding the potato in a layer of steam that researchers thought might leave it undercooked and undesirable.
“Ask any chef and they will confirm that the physics and chemistry behind food is a complex and fascinating subject that bubbles over to other science disciplines,” says Professor Thodoris Karapantsios from the Aristotle University of Thessaloniki, and member of the research team behind the studies.
To study how microgravity influences cooking techniques such as frying, a novel experimental carousel-type apparatus was designed to be safe while also operate in weightlessness. The experiments were conducted on two ESA parabolic flight campaigns, whereby an aircraft flies in repeated arcs to recreate brief moments of weightlessness.
The experiment filmed the frying process with a high-speed, high-resolution camera to capture the bubble dynamics such as growth rate, size and distribution, as well as the escape velocity from the potato, the bubbles’ speed and direction of travel in the oil. The experiment measured the temperature of the boiling oil as well as temperatures inside the potato.The experiment hardware is automated and closed for safety. It maintains a constant pressure inside the frying chamber to avoid leaks, to prevent the oil from sloshing around and to use less energy in heating.
The researchers from the University of Thessaloniki, Greece, found that shortly after the potato was added to the oil in low gravity conditions, vapour bubbles detached easily from the potato surface similarly to on Earth. While more research is needed to fine-tune some parameters, it does indicate that astronauts will be able to have more than re-hydrated food on the menu as they explore new worlds.
RUBIN OBSERVATORY BRINGS A UNIVERSE OF DISCOVERY TO THE PUBLIC
NSFNoirLab
The Vera C. Rubin Observatory Education and Public Outreach (EPO) programme launches today with a suite of online, interactive experiences showcasing Rubin Observatory, its technology, and its science. This multifaceted programme employs new technologies and proven strategies to reach the widest possible audience, including science-interested teens and adults and those who are not already engaged with or knowledgeable about astronomy and astrophysics.
The entire programme is online at rubinobservatory.org and also optimized for mobile devices, allowing anyone to access the entire suite of materials developed by the Rubin EPO team. Materials are available in English and Spanish, to welcome a Chilean audience as well as Spanish speakers in the United States and around the world.
Rubin Observatory is a partnership supported equally by funding from the US National Science Foundation (NSF) and the US Department of Energy (DOE) and is operated by NSF’s NOIRLab and SLAC National Accelerator Laboratory. Rubin Observatory is an integrated system consisting of an 8.4-meter telescope, a 3200-megapixel camera, an automated data processing system, and an online public engagement platform.
Rubin’s EPO program is the first astronomy outreach programme to be fully funded by the NSF for creation during a project’s construction phase along with the rest of the observatory system. The construction and operations of Rubin Observatory and the DOE-built LSST Camera are supported by a US federal partnership of the NSF and DOE, along with private and international contributors. The observatory itself is still under construction, but the EPO programme, which was less affected by pandemic-related delays, finished ahead of schedule and under budget.
A pillar of the Rubin EPO programme is its formal education component, which focuses on engaging advanced middle-school to introductory college students with real telescope data. The programme centres around a series of investigations and a full complement of teacher support materials. Investigations are engaging and interactive and don’t require special software or for teachers to download data — they just need a browser. Best of all, they’re free for anyone to use. Rubin’s formal education team has also started offering professional development workshops to introduce teachers to the investigations and connect them with the Rubin Observatory community.
The Rubin EPO programme also offers a range of products for the general public, including a website, animations and videos, an image gallery, and a browser-based game called Space Surveyors. The game teaches players how a survey telescope works as they attempt to capture images of stars, galaxies, and moving objects in the night sky — just as Rubin Observatory will when it begins operating in late 2024.
“The programme built by Rubin Observatory's EPO team is exciting and unique — there's nothing else like it out there. It's an opportunity for teachers and the public to interact with science data in a whole new way,” says Elizabeth Pentecost, Project Management Administrator at NSF.
"Astronomy expands our knowledge of the Universe and inspires us to learn more about science and the natural world. Rubin Observatory is merging these two elements into a truly unique Education and Public Outreach programme that uses online programmes to educate and engage audiences around the world who are hungry to learn," said Bob Blum, Director for Operations, Vera C. Rubin Observatory, NSF’s NOIRLab.
Additional education and outreach products will be released once data are flowing from the observatory. These include the Skyviewer, an all-sky visualization tool and the Orbitviewer, a Solar System visualization tool. Rubin Observatory, in partnership with Zooniverse, will also offer scientists an easy, browser-based tool to create citizen science projects and populate them with Rubin data.
Topic: Early June Astronomy Bulletin (Read 525 times)