Daily Archives: June 4, 2021

COLUMBIA, Md., June 4, 2021 /PRNewswire/ --Astronomers are still trying to understand how stars and galaxies formed in the early universe. Now,scientists,using theStratospheric Observatory for Infrared Astronomy, (SOFIA), have new clues from a glowing nebula filled with clouds of hot gas and dustknown as RCW 120. Data from SOFIA suggestthat this nebula may be representative of how stars formed in the early universe.

Scientists using SOFIA, a joint project of NASA and the German Space Agency at DLR, found the stellar wind emanating from the nebula's central massive star is making the nebula expand rapidly. The expansion is triggering the birth of stellar neighbors at breakneck speeds and revealing the nebula is younger than previously believed. The results are published in Science Advances.

Located in the southern Milky Way about 4,300 light years from Earth, in clouds near the constellation Scorpius, researchers discovered that the powerful stellar winds are expanding the nebula incredibly fast at 33,000 miles per hour (or 53,000 km per hour), which corresponds to 15 kilometers per second. The surrounding gas clouds are getting compressed as the nebula pushes into them triggering the birth of new stars near the clouds' edges."

The speed of expansion was also used to determine the nebula's age. It turns out RCW 120 is much younger than previously believed, having formed less than 150,000 years ago.

"The nebula is giving us a window into what star formation may have been like in the early universe," said Dr. Matteo Luisi, a postdoctoral fellow at West Virginia University in Morgantown, West Virginia. "We can't go back to study the early universe, so we depend on observations like these to understand how the universe transformed from the Big Bang to the universe we see today."

Astronomers call the effects stars have on their neighbors' creation "feedback." But exactly how feedback can help or hinder star formation is still somewhat of a mystery. SOFIA previously found that a stellar wind in the Orion Nebula is clearing a bubble free of material needed to form new stars. Now, in the nebula RCW 120, the energy from the original star is triggering the birth of new generations.

The nebula's young age suggests that star formation triggered by an existing star's feedback can happen very quickly and may have been responsible for the high rate of star formation in the universe's earliest eras.

The observations were made while flying in the skies above Christchurch, New Zealand, in 2019. Using SOFIA's instrument called the German Receiver for Astronomy at Terahertz Frequencies, or GREAT, researchers studied the chemical fingerprint of ionized carbon gas to measure the nebula's expansion speed. Unlike infrared images, this fingerprint measures how fast the gas is moving, which can be used to learn how existing stars are affecting future generations. These results are part of an international project to understand the effects of stellar feedback in a variety of star-forming regions.

ABOUT SOFIA

SOFIA is a joint project of NASA and the German Aerospace Center. NASA's Ames Research Center in California's Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA's Armstrong Flight Research Center Building 703, in Palmdale, California.

ABOUT USRA

Foundedin 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA), is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs, under Federal funding. USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise.More information about USRA is available at http://www.usra.edu.

PR Contact: Suraiya Farukhi, Ph.D.[emailprotected] 443-812-6945

SOURCE Universities Space Research Association

http://www.usra.edu

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Young Nebula Hints at Formation of Stars in Early Universe - PRNewswire

When the pandemic shut down in-person activities, UC Riversides Recreation Department moved its youth and recreation programming online. In the months since, department leaders say they have hit their stride in virtual programming.

The department offers youth camps and programming for pre-teens and teenagers. Shifting those online was challenging as counselors learned what worked best in a virtual environment, said Carl Dugdale, youth program coordinator.

Its definitely more targeted now, Dugdale said. We definitely found our footing.

Last year for its annual Camp Highlander, which normally offers outdoor activities, counselors offered online courses in subjects such as baking, American Sign Language, and coding. Aquatics instructors provided customized swimming lessons for kids with home pools and began a pen-pal program.

The Recreation Department has decided to skip its usual summer session for Camp Highlander and plan for the fall, when in-person activities can resume.

Meanwhile, the department has found success with interactive online programs in three areas: astronomy, neuroscience, and dance squad. About a dozen UCR student volunteers and staff members serve as instructors.

For the Dance Squad classes, instructor Emily Thomas keeps kids energized by blending dance with games, chats, and other activities, Dugdale said.

The astronomy sessions have been among the most popular, featuring interactive software and activities.

For example, one session involved the illustration of a 3D model of the solar system using software. Another exercise involved students creating their own simulations of exoplanets, said Xinnan Du, an outreach director and postdoctoral scholar in astronomy who has overseen the astronomy sessions.

The astronomy nights began with about 35 registered participants in summer 2020, but for the spring session that has grown to 257. A YouTube livestream was created in addition to the Zoom sessions.

One overarching goal of ours is to have the community stay together during these difficult times and to feature some fascinating ideas and concepts in astronomy in the curriculum, said Du, who is joined by graduate student instructors at the classes. It also provides the participants with an opportunity to talk to experts and students in the field.

As part of the move to virtual, Dugdale said the audience has expanded beyond Riverside, with some participants joining from as far as the East Coast.

As a parent himself, Dugdale said he wanted to provide parents a safe and engaging space for their children while also giving them a break a few hours a week.

We wanted to support campus, families, and the further-away communities, particularly with the stress families have been going through with school and life in general, he said.

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Recreation Services finds success with virtual programming - UC Riverside

Heres what the biggest giant planet in our solar system, Jupiter, looks like. The Juno spacecraft captured this image during its 31st close flyby of Jupiter on December 30, 2020. The storm known as the Great Red Spot is visible on the horizon, nearly rotated out of view. Citizen scientist Tanya Oleksuik created this color-enhanced image using data from the JunoCam camera. Image via NASA.Our solar system is normal

In late May 2021, astronomers released new results in a 30-year census of planetary systems beyond our own. The results show that most are arranged much like our solar system. That is, most giant exoplanets arent close to their parent stars, but instead live in the suburbs of their systems. Thats contrary to what astronomers thought when first discovering giant exoplanets in the 1990s. For awhile, they thought hot Jupiters giant planets close to their stars might be the norm. Now the California Legacy Survey, which began in the 1990s, has proven otherwise. The newly released census results describe our solar system as normal. Or, as astronomer Andrew Howard of Caltech said in a statement:

Were starting to see patterns in other planetary systems that make our solar system look a bit more familiar.

The results were published on May 25, 2021, in two studies (here and here) in the peer-reviewed Astrophysical Journal Supplement.

Our solar system is arranged with the rocky, terrestrial planets closest to our sun and the gas giant planets farther out. Astronomers typically speak of distances in planetary systems in astronomical units (AU). One AU is the same as Earths distance from the sun, or 93 million miles (150 million km). Jupiter lies 5 AU from our sun. Saturn lies 9 AU from our sun. The survey showed that giant exoplanets mostly live within 1 and 10 AU from their parent stars.

Giant planets have a big impact on the formation of their planetary systems. Astronomer Lauren Weiss of the University of Hawaii Institute for Astronomy commented:

Dynamically speaking, Jupiter and Saturn are the VIPs Very Important Planets of the solar system. They are thought to have shaped the assembly of the terrestrial planets, potentially stunting the growth of Mars and slingshotting water-bearing comets toward Earth.

Astronomers didnt begin finding planets orbiting distant stars until the 1990s. They often find the largest gas giant planets because these planets are so massive. On the other hand, the California survey was unable to include smaller gas giant planets in the range of Uranus (19 AU) and Neptune (30 AU). They were able to note that planets the size of Jupiter and Saturn were uncommon as far out as Uranus and Neptune, however. BJ Fulton of Caltech explained:

While we cant detect smaller planets similar to Neptune and Uranus that are very distant from their stars, we can infer that the large gas giants like Jupiter and Saturn are extremely rare in the outermost regions of most exoplanetary systems.

The survey data reveal that for every 100 stars in our Milky Way galaxy, there are likely to be at least 14 cold giant planets. We dont know for sure how many stars our Milky Way contains, but its probably between 100 and 400 billion stars. Extrapolating from the number of giant planets detected around nearby stars, astronomers believe the Milky Way galaxy teems with billions of giant planets.

The survey targeted 719 sunlike stars for more than 30 years. It analyzed 177 planets, including 14 newly discovered gas giants. The planets have masses between 1/100 and 20 times the mass of Jupiter. (For comparison, Jupiter is 318 times as massive as Earth. In fact, Jupiters mass is 2.5 times that of all the other planets in our solar system combined.)

The team designed the survey to be unbiased by selecting random stars. Lee Rosenthal of Caltech explained they chose the survey members:

As if you could put your hand in a grab bag of stars and pull a random planet out.

When astronomers first began discovering exoplanets in the 1990s, they wondered if our solar system was unusual. That was because most of the first planets to be discovered were hot Jupiters, similar in mass to Jupiter but orbiting very close (less than 1 AU) to their parent stars. But, as it turns out, one of the primary methods used to discover exoplanets was biased in favor of finding these large and close-in planets. That planet-hunting method, called radial velocity method, watches for a wobble in a stars motion produced by the tug of a planet. And, of course, nearby giant planets tugged the hardest. Rosenthal said:

The hot Jupiters were easy pickings back then, but those early surveys were biased and didnt get the full picture.

The span of 30-some years since then has improved planet-hunting technologies. Now astronomers can detect a stars wobble from a planet orbiting far from it. And so the long-term California Legacy Survey has produced a wide range of results. As Fulton said:

The idea is to survey planets of all sizes and temperatures and then to look for patterns in the data.

The team is looking forward to new instruments that will help them see more and learn more about distant exoplanets. One instrument is the Keck Planet Finder, which may be ready as soon as 2022. The Keck Planet Finders main goal will be to measure the masses and orbital properties of small planets including Earths, super-Earths, and sub-Neptunes. The Planet Finders principal investigator is Andrew Howard of Caltech. He said:

This survey is a great jumping-off point for future instruments that are sensitive to planets the size of Earth.

Bottom line: Astronomers released the results of a 30-plus-year survey of exoplanets that found that giant planets live at a similar distance from their host star as we see here in our own solar system.

Source: The California Legacy Survey I. A Catalog of 177 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades

Source: The California Legacy Survey II. Occurrence of Giant Planets Beyond the Ice line

Via Caltech

Via Keck Observatory

Kelly Kizer Whitt has been a science writer specializing in astronomy for more than two decades. She began her career at Astronomy Magazine, and she has made regular contributions to AstronomyToday and the Sierra Club, among other outlets. Her childrens picture book, Solar System Forecast, was published in 2012. She has also written a young adult dystopian novel titled A Different Sky. When she is not reading or writing about astronomy and staring up at the stars, she enjoys traveling to the national parks, creating crossword puzzles, running, tennis, and paddleboarding. Kelly lives with her family in Wisconsin.

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Giant planets live in the suburbsGiant planets live in the suburbs - EarthSky

On May 26 2021, The African Astronomical Society (AfAS) and the Office of Astronomy for Development (OAD) signed a five-year partnership Memorandum of Agreement (MOA) that sees the two collaborating towards bringing together complementary resources, networks and expertise to advance development through astronomy throughout the African Continent.

We are pleased to formalise an existing strong relationship with AfAS, said OAD Director Kevin Govender, who added: Over the past decade, the African continent has demonstrated beyond doubt its significant position in the global astronomy landscape. The rapid growth of this field of research combined with the energy and enthusiasm of the continents youth, as well as significant astronomy infrastructure projects on the continent, all make it time for this agreement to be signed between AfAS and the OAD.

The agreement envisages areas of collaboration that include:

It was just natural that both organisations join hands and work in synergy for the benefit of all the stakeholders to ripe societal and economic benefits by them bringing together their respective resources, networks, and expertise, said AfAS President Professor Jamal Mimouni, who jointly signed the agreement with Govender.

AfAS will provide the necessary human resources and communications channels to develop, implement and promote joint initiatives with the OAD. As appropriate, AfAS will invite representation from the OAD on its various committees and sub-committees.AfAS will also actively collaborate with the OAD and the National Organising Committee of the General Assembly 2024; to promote it and encourage active participation by African astronomers and students.

The OAD will provide the necessary human resources and communications, logistics and publicity channels to develop, implement and promote joint initiatives with AfAS. The OAD will also endeavour to synergise its fundraising activities through the IAU Fundraiser and include, as appropriate, AfAS representation in its fundraising initiatives.

AfAS and the OAD are both funded and supported by the South African Department of Science and Innovation (DSI) and have always enjoyed a close working relationship. This MOA formalises the partnership between the two, aimed primarily at strengthening development through Astronomy in Africa.

AfAS:AfAS is a Pan-African astronomy professional society that creates a globally competitive and collaborative astronomy community in Africa. It was established in 2010 and relaunched in 2019. Its mission is to be the voice of astronomy in Africa and address Africas challenges through astronomy promotion and advancement.

The OAD:The OAD was established in 2011 by the International Astronomical Union (IAU) in partnership with the South African National Research Foundation (NRF). The OAD is a vital component of the IAUs strategy to use astronomy for sustainable global development. The mission of the OAD is to help further the use of astronomy, including its practitioners, skills and infrastructures, as a tool for development in every country by mobilising the human and financial resources necessary to realise the fields scientific, technological and cultural benefits to society.

Mustapha has a strong relationship with written words and enjoys elaborating on minor details with a plethora of information.

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AfAS and the IAU-OAD Sign Cooperation Agreement to Strengthen Development Through Astronomy In Africa - Space in Africa

Fast-moving Mars and Venus make eye-catching arrangements with Pollux and Castor this month, before the twin stars annual departure into the evening twilight glow. Even the slow motions of Jupiter and Saturn can be noted with careful attention to background stars.

The moon pairs up with four of the five naked-eye planets and four of the five zodiacal first-magnitude stars. Venus presents its northernmost setting of 2021 on June 4, 16 days before the sun does so. The aptly named Summer Triangle is visible from dusk until dawn from late June until early August.

In Junes evening twilight: The only planets visible at dusk are bright Venus, of magnitude -3.8, very low in the west-northwest, and faint Mars, of magnitude +1.8, some 25 to 7 degrees to Venus upper left. The brightest stars visible, both of zero magnitude, are golden Arcturus, very high in the southeast to south-southwest, and blue-white Vega, climbing high in the east-northeast.

In early June, the Spring Arch of four stars is still visible: Procyon, low in the west; twins Pollux and Castor, atop the arch and 4.5 degrees apart in the west-northwest; and Capella, low in the northwest. The twins remain visible at months end, but only with the aid of binoculars.

Watch for these striking arrangements of planets with twin stars Pollux and Castor: Mars, on June 7, is 7 degrees to the left of Pollux and forms a straight line with the twins. Venus, on June 13, forms an isosceles triangle with the twins. On June 21, Venus passes 5.2 degrees to the south (lower left) of Pollux, its least distance from that star. On June 24, Venus is 6.5 degrees to the left of Pollux and forms a straight line with the twins.

Other stars visible at dusk: Regulus, heart of Leo, is in the west-southwest to west, to the upper left of Venus and Mars. (Mars closes to within 18 degrees of the lower right of Regulus at months end.) Spica, the spike of grain in the hand of Virgo, crosses through south into south-southwest, 33 degrees to the lower right of or below Arcturus. Antares, heart of the Scorpion, starts very low in the southeast and climbs into the south-southeast. Look for Deneb to the lower left of Vega. Watch the horizon a little more than 10 degrees north of east, to Vegas lower right, for the rising of Altair, completing the Summer Triangle with Vega and Deneb.

Follow the moon for two weeks as it waxes from a thin crescent on June 11 to full on June 24. Watch for its pairings with planets and bright zodiacal stars on the evenings of June 11 (Venus); 12 (Pollux); 13 (Mars); 15 (Regulus); 19 (Spica); and 22 (Antares).

All these events are illustrated on the Sky Calendar for June 2021. To subscribe for $12 per year (for three printed monthly issues mailed quarterly), or to view a sample issue, visit http://www.abramsplanetarium.org/skycalendar.

At end of June, Saturn rises in the east-southeast within two hours after sunset, and brighter Jupiter rises within an hour later, nearly 20 degrees to the lower left of Saturn.

In coming months, watch for changes in setting place of the evening star. Venus, at magnitude -3.8, sets in the west-northwest between 1.4 and 1.7 hours after sunset this month. On June 4, Venus attains a declination of +24 degrees, 26 minutes north of the Earths equator, and sets farthest north, 30 degrees north of west (as seen from our latitude, 34 degrees north). After little change for nearly two weeks, youll notice the start of a dramatic swing in Venus setting place during this apparition, to a declination of -27 degrees, 15 minutes, on Nov. 6. Venus will then set 33 degrees south of westa southward shift in azimuth of 63 degrees in five months!

On June 17 and 18, Venus follows the sun down to the horizon, on same arc, but trailing sun by 96 minutes.

The summer solstice, sun standstill, occurs on June 20, as the sun reaches its northernmost position, directly over the Tropic of Cancer, at 8:32 p.m. Earlier that day in Palm Springs, our highest sun of the year passes just 10.4 degrees south of overhead at 12:48 p.m.

In Junes morning twilight: Look to the southern sky at dawn to see Jupiter, of magnitude -2.4 to -2.6, the brightest morning star, and Saturn, three magnitudes fainter at +0.6 to +0.4, between 18 and 20 degrees to Jupiters right or lower right. Watch these planets move! Use binoculars before twilight begins to view the fourth-magnitude star Iota in Aquarius, about 3 degrees from Jupiter all month. Jupiter begins to retrograde on June 20, and will go 10 degrees west in the next four months, ending on Oct. 17. Jupiter will pass about 1 degree from Iota on Aug. 6 and Dec. 20, completing a triple conjunction with that star. Binoculars will also show fourth-magnitude Theta in Capricornus, 0.7-1.7 degrees west-southwest of Saturn this month. Saturns retrograde of nearly 7 degrees, which started on May 23, will continue until Oct. 10, when the ringed planet will be 7.3 degrees west-southwest of Theta.

Antares makes its exit in the southwest in Junes morning mid-twilight sky, and Arcturus departs in the west-northwest, both in the second week. (By end of June, they set more than two hours before sunup.) TheSummer Triangleof Vega, Altair and Deneb passes west of overhead, while Fomalhaut,mouth of the Southern Fish, glows low in the southeast to south, 20 degrees below or to the lower left of Jupiter.

Capella appears very low in the north-northeast at the start of June, and rises higher into the northeast as the month progresses. Late in June, look for Aldebaran, eye of Taurus, the Bull, very low in the east-northeast, 31 degrees to the lower right of Capella. On Junes last two mornings, use binoculars to spot first-magnitude Mercury rising 8 degrees to the lower left of Aldebaran. Mercury will brighten further and be easier to spot during the first three weeks of July.

Watch the waning gibbous moon pass Saturn and Jupiter on the mornings of May 31 and June 1, and on June 27-29. In Junes morning twilight, the waning moon can be followed during the first and last weeks of month, June 1-7 and 24-30.

The solar eclipse of June 10 can NOTbe seen from California. An annular, or ring of fire, eclipse will occur within a path through Canada and the arctic, while parts of the eastern and north-central U.S. will see a partial eclipse near sunrise. Coachella Valleys next chances to view a solar eclipse will come on Oct. 14, 2023, and Apr. 8, 2024.

Robert Victor was a staff astronomer at Abrams Planetarium at Michigan State University. When the coast is clear, he looks forward to sky-watching sessions, in time for a fine display of three planets in the evening sky in autumn 2021. Robert Miller, who provided the twilight charts, did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

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June Astronomy: As the Summer Begins, Mars and Venus Engage in a Cosmic Dance with Pollux and Castor - Coachella Valley Independent

A newly formed star is surrounded by a rotating disk of gas and dust, called a protoplanetary disk. This disk, illustrated here around a brown dwarf, provides the materials for planet formation. Credit: NASA/JPL-Caltech

Many of us remember those school-room models of our Solar System, with tiny wooden planets rotating at the ends of their wires around a bright-orange painted sun. But how accurate is the model? Do the planets really align in a plane, or do their orbits crisscross around the sun at different angles? It turns out the toy isnt too far off, at least in this one aspect.

Our solar system is actually pretty flat, with most of its planets orbiting within three degrees of the plane of the Earths orbit around the sun, called the ecliptic. This flatness extends to the asteroid belt between Mars and Jupiter, though some members of the region of icy objects past Neptune called the Kuiper belt are more extreme, with inclinations up to 30 degrees.

This relative flatness, which is not an unusual feature of solar systems, results from how stars and planetary systems typically form. The process begins with a slowly rotating, roughly spherical cloud of gas and dust, about one light year across. Eventually, a portion of this material collapses toward the center, forming a star, and the spinning cloud begins to flatten into a disk due to its rotation. Its out of this rotating protoplanetary disk of gas and dust that planets are then spun out, resulting in a relatively flat solar system. Eventually, when most of the gas has settled onto the star or planets or has dissipated, the system is left with a debris disk of planetary leftovers, like our own asteroid-strewn Kuiper belt.

Some astronomers at Penn State study protoplanetary and debris disks to get a better idea of how planetary systems form. But not all stars and planets form in exactly the same manner and not all planetary systems are flat.

The interdisciplinary nature of astronomy research at Penn State, including at the Universitys Center for Exoplanets and Habitable Worlds, allows its scientists to paint a bigger picture of the formation and evolution of planetary systems.

Its an exciting time, because so many planets have been discovered in other solar systems, for example by NASAs Kepler space telescope and Transiting Exoplanet Survey Satellite (TESS), and a lot of them look very different from the planets in our solar system, said Rebekah Dawson, Shaffer Career Development Professor in Science and assistant professor of astronomy and astrophysics. So, we have to come up with new ways of thinking about planet formation that can account for the diversity of planets we now know about.

In addition to studying disks, researchers like Dawson study the exceptions to the norm, unusual stars and planets that could support or make us rethink current theories. Together, these investigations are helping scientists improve our understanding of how and where different kinds of stars and planets form, and what makes a planet habitable.

While some researchers study mature systems and infer aspects of the planet formation process, Assistant Professor of Astronomy and Astrophysics Ian Czekala tries to catch planetary formation in the act.

I study the protoplanetary disks that surround young stars for the first 10 million years of their lives, he said. That may sound like a long time period, but its actually very small compared to a stars total lifetime. Our sun, for example, is about five billion years old; most of the exoplanet systems that people study are a least a billion years old.

While Kepler and other survey missions have found thousands of mature solar systems, there are fewer nearby protoplanetary systems that easily lend themselves to detailed study. To investigate these early systems, Czekala uses the Atacama Large Millimeter/submillimeter Array (ALMA), one of the most complex astronomical observatories ever built. Located in Chile, ALMA uses a network of high-precision antennas working together to provide a high-resolution look at the universe, using wavelengths of light between the infrared and radio regions of the electromagnetic spectrum.

Example of a protoplanetary disk surrounding young binary stars. The gas and dust in these disks produce cold thermal emissions that can be detected at the millimeter wavelength. Credit: ALMA (ESO/NAOJ/NRAO), I. Czekala and G. Kennedy; NRAO/AUI/NSF, S. Dagnello

ALMA can directly detect the gas and dust in protoplanetary disks, which produce very cold thermal emissions (20 to 30 degrees Kelvin, or -400 to -424 degrees Fahrenheit) at millimeter wavelengths. Czekala uses gas in the disk, including carbon monoxide, as a tracer to determine how the disk is rotating. This data provides a glimpse of the disks dynamics, building a sort of three-dimensional picture as a function of velocity. Some disks show gaps that might be produced by a planet orbiting in that space.

Whats interesting is not just that we see the disk rotating, but that we are starting to sense the ways in which the velocity of the field deviates from its expected rotation at a very subtle level, said Czekala. Its like watching a river flow downstream. Sure, you see the bulk flow of the river, but when you look at the eddies and turbulent waves, you can infer that there might be a submerged rock in one area or even a large underwater cavern in another. Its what lies underneath that gets me really excited.

Dawson in some cases studies debris disks, but she is also very interested in understanding the formation of planets that look nothing like those in our solar system. In particular, she is studying how planetary orbits might have changed in an early solar system, which can tell us how planets came to be where they are today.

When talking about theories of planet formation, there is some debate about where planets form, even if the processes involved in those different locations may have some similarities, she said.

Some of Dawsons researchhas focused on large gas giant planets called hot Jupiters that are similar in mass to our own Jupiter but are found unexpectedly close to their stars. Because of the proximity to their stars, these planets have a surprisingly short orbit of only three or four days.

There are several theories about how hot Jupiters formed. One suggests that they formed where they are currently located, close to their stars. Another theory suggests that they formed farther away, but a disturbance of some sort exhibited a gravitational force that made the hot Jupiters orbit extremely elliptical in a way that it passed very close to its star. Eventually, the pull of the star produced tides on the planet that caused its orbit to shrink and become more circular.

An artists depiction of a hot Jupiter gas giant planet, which are similar in mass to our own Jupiter but are found unexpectedly close to their stars. Penn State astronomer Rebekah Dawson studies the history of planetary systems with hot Jupiters by investigating how these large planets came to be so close to their stars. Credit: NASA/JPL-Caltech

To try to disentangle these possible formation pathways, we sometimes use computer simulations of the process, which leads to other expectations for the properties of hot Jupiters, said Dawson. We can then compare observed properties of hot Jupiters based on visible and infrared observations of their stars with the simulations to see if they are consistent with a particular theory. We can also look for planets in the same system as the hot Jupiters for clues to their formation.

If a hot Jupiter forms near its star, for example, its plausible that other planets formed nearby that could be observed. But if it is formed through the pathway with a highly elliptical orbit, its likely that any other planets between the hot Jupiter and the sun would get ejected or collide with it.

What we see in the data is that most Jupiters dont have other planets nearby, but there are a few exceptions, said Dawson. Ive come to believe that none of these theories can explain all of the hot Jupiters that we see. There may be different ways to make a hot Jupiter, and thats probably true of other types of planets that we see that dont look like the planets in our solar system.

Just as the study of unusual planets like hot Jupiters can help us understand fundamental processes, so too can the study of unusual stars. Stars exist across a wide range of masses, the heaviest of which is 150 times the mass of our sun. The lightest stars, known as brown dwarfs, are less than one-tenth the mass of the sun and therefore can be cool and faint enough to look like a gas giant planet.

Kevin Luhman, professor astronomy and astrophysics, has spent much of his career studying how brown dwarfs are like stars and how they are like planets. To determine if they are born more like stars or planets, he is trying to identify the smallest mass at which brown dwarfs exist.

There are different theories about the formation of stars that make different predictions for the minimum mass at which brown dwarfs exist, he said. If you can measure that minimum mass, you can test theories of how stars are born.

Because they are cool and faint, brown dwarfs can also be challenging to find; the first wasnt discovered until 1995. However, when they are very young, brown dwarfs are relatively bright almost as bright as other stars making them easier to detect.

This illustration shows the relative sizes of a hypothetical brown dwarf planetary system compared to our own solar system. Penn State astronmer Kevin Luhman studies how small, cool brown dwarfs are similar to planets and how they are similar to stars, which will provide insight into the process of star and planet formation. Credit: NASA/JPL-Caltech/T. Pyle (SSC)

We look for newborn brown dwarfs in nebulas of gas and dust that are already known to be giving birth to stars, like the nearby Orion Nebula, said Luhman. Much of my work has involved searching these nebulas, using very sensitive telescopes that are able to see them.

Luhman has helped identify brown dwarfs as small as five times the mass of Jupiter, which overlaps with the masses of some planets. He hopes that the launch of the James Webb Space Telescope in 2021 will allow astronomers to determine the minimum mass of these unusual stars.

Brown dwarfs tend to be brightest in the infrared, and James Webb will be the most powerful infrared telescope to date, he said. We also hope to answer whether and how often planets can form around brown dwarfs. Theres already good evidence of protoplanetary disks existing around brown dwarfs, meaning they have the building blocks for making planets around them.

These questions will help inform the bigger picture about planet formation, including whether planets form around any kind of star or only stars like the sun and, of course, whether it is possible for planets around brown dwarfs, if they exist, to harbor life.

While star and planet formation might be thought of as separate fields of research, the processes involved are all intrinsically linked. Protoplanetary disks not only spawn planets but continuously funnel gas and dust onto the young star. And the very act of planet formation changes the structure of the disk, which may affect the subsequent planets that form in the same disk. Its somewhat of a chicken and egg scenario, according to Czekala.

In this way, its useful to have a variety of researchers using different tactics to study these processes all in one place. The interdisciplinary nature of astronomy research at Penn State, including at the UniversitysCenter for Exoplanets and Habitable Worlds, allows its scientists to paint a bigger picture of the formation and evolution of planetary systems.

Were trying to piece together the processes of star and planet formation, but we only glimpse clues here and there, which we need to use to guide us to a holistic theory, said Czekala. New observations always lead to a bloom of new theories, but at the end of the day the big picture needs to hang together, including the implications for the formation epoch that were studying with the protoplanetary disks. We have a unique opportunity to bring the different communities together.

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Spinning Disks, Oddball Stars, and Strange Planets Help Astronomers Test Theories About Planetary System Formation - SciTechDaily

In June of 1769, an astronomer named David Rittenhouse prepared to observe a rare cosmic phenomenon, the transit of Venus. Rittenhouse had built an observatory on his farm in Pennsylvania to monitor the planet as it moved across the face of the sun, a small black dot against the glowing orb in the afternoon sky. When the moment arrived, Rittenhouse became so over-excited that he collapsed and fainted, missing the beginning of the most important event of his scientific life, writes the historian Andrea Wulf. When he regained consciousness, he quickly grabbed his telescope to discover that Venus had already entered the sun, but calmed himself sufficiently to take some observations."

Astronomers across the globe entered a similar state of feverish excitement yesterday. There have been no reports of faintingyetbut just like Rittenhouse, they are overwhelmed by a new opportunity to experience our next-door neighbor.

NASA has picked not one, but two new spacecraft missions to study the second planet from the sun. The missionsa probe that will plunge into Venuss atmosphere and an orbiter that will remain circling overheadare expected to leave Earth at the end of this decade. All day, the astronomy community waited for NASA Administrator Bill Nelson to make an unspecified announcement about future missions, and when he spoke the word Venus, planetary scientists, to use less-than-scientific parlance, kind of lost it. There's a spacecraft in orbit around Venus nowa Japanese spacecraft called Akatsukibut NASA hasnt sent a mission to the planet in more than 30 years. One mission would have been thrilling, but two feels almost surreal.

The decision was particularly satisfying for many planetary scientists, especially those who believe that NASA has overlooked Venus in favor of our other next-door neighbor, Mars. In the past three decades, NASA has sent more than a dozen robots to the red planet. Where was the love for Venus?

After all, we owe quite a bit of our understanding of the universe to this shining planet. It was Venus that helped prove the Copernican theory that the sun, not Earth, was at the center of our solar system. When Galileo saw Venus thinning into a crescent in his telescope, moving through phases just like our moon, he deduced that the planet must be reflecting sunlight in its orbit around our star. Centuries later, when people began to dispatch machines into the solar system, the first to reach another planet crash-landed on the Venusian surface in 1966. The earliest missions, dispatched by the Soviet Union, revealed an inferno of a planet, with scorching temperatures that melted the spacecraft that managed to touch down.

You have to forgive Venus for that: It wasn't always this way. Billions of years ago, the planet was balmy and as comfortable as Earth, likely with an ocean of its own, before its atmosphere ballooned with heat-trapping gases and its water vanished into space. That history, combined with similarities between Earth and Venus in size and composition, is why planetary scientists refer to the planets as twins. But its not hard to see why NASA has chosen to focus on another sibling. Mars has a surface that wont melt robots, and while exploration there isnt easy, the agency has gotten confident enough that engineers have managed to fly a first-of-its-kind helicopter without crashing. For a space agency that has long promised to send astronauts to Mars, the attention makes sense.

Astronauts may never visit the planet, but Venus is one of the most exciting targets in the search for life beyond Earth, the drive to answer that most existential of questions. Last fall, a group of scientists announced that they had discovered evidence of a rare, stinky gas called phosphine floating around in Venuss clouds. Phosphine cant survive for long in Venuss acidic atmosphere, so presumably something was replenishing the supply. The scientists suggested that the mysterious something could be a chemical process no one has ever seen before or, just maybe, a form of alien life. On Earth, phosphine is produced by microorganismswhy not on this other planet too? Mars might have ancient microbes fossilized in its rock, but Venus could have lifeforms suspended in its clouds.

Since that initial discovery, other scientists have raised doubts about the researchincluding whether any phosphine is actually there. Debates like this have a tendency to linger, and phosphine discussion might still be going in 2028, when one of the new Venus missions is supposed to launch. (Consider that scientists spent 15 years debating the presence of methane gas on Mars before reaching some consensus, and they still disagree over whether its being produced by chemical processes or living organisms hiding out of view.) Although the new Venus missions are not designed to search directly for signs of phosphinescientists had already submitted their mission concepts to NASA when the news broke last yearthe probe meant to dive into the atmosphere could potentially do some sniffing around.

Venus holds many more mysteries for the science community. The atmospheric mission, known as DAVINCI+, will determine whether the planet had an ocean, as scientists suspect. The orbiting mission, called VERITAS, will map Venuss surface in fine detail and investigate whether the planet has active volcanoes and shifting plate tectonics like Earth. Were gonna have a totally different view of it when were done, Tom Wagner, a NASA scientist who leads the program that decided to fund these journeys, told me. Kids who learn about this stuff in 20 years are going to have a very different perspective on Venus than we do."

The latest Venus news is understandably big news for space scientists, but the rest of us, who have little reason to contemplate the wonders of the universe in our daily lives, might be wondering: Why should we explore Venus? Why should we visit Io, a volcanic moon of Jupiter, and Triton, an icy moon of Neptunethe other targets that NASA had considered for new missionsor any worlds beyond Earth at all? Well, these places, in a cosmic sense, are all we have. We dont have the technology to dispatch probes to planets around other stars. We will remain, certainly in this lifetime and probably for centuries to come, within the bounds of this solar system. Venus, Mars, the distant moons of the outer planetsthese may be the farthest worlds that humankind and its robotic explorers will ever reach. In some ways, these are already the most familiar bodies in the solar system; in others, we are only beginning to discover them.

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NASA Is Giving Two Venus Missions a Chance - The Atlantic

The most ancient spiral galaxy found so far, called BRI 1335-0417, at an distance of 12.4 billion light-years and at a time just 1.4 billion years after the Big Bang. Spiral arms are visible on both sides of the compact, bright area in the galaxy center. Image via ALMA/ T. Tsukui & S. Iguchi.

Swirly and beautiful, spiral galaxies are what we often think of when someone mentions the word galaxy. Our own Milky Way is a spiral galaxy. These galaxies are pretty common in the nearby universe. But the farther back in time and distance astronomers look, the fewer spiral galaxies they see among the multitudes of galaxies in our universe. Instead, as we go out into space and back in time galaxies appear more irregular in shape. And thus how and when spiral galaxies formed is one of astronomys classic questions. And so it was with some excitement on May 20, 2021 that astronomers reported the most ancient spiral galaxy yet found.

This galaxy is labeled BRI 1335-0417. It existed only 1.4 billion years after the Big Bang, which equals a distance from us of 12.4 billion light-years. So far away so far back in time and yet this galaxy has clearly visible spiral arms! Clearly, this galaxy has an important contribution to make in answering questions about spiral galaxies origins.

The astronomers published a paper on their findings in the peer-reviewed journal Science on May 20, 2021.

Galaxies come in many different shapes and are classified by their morphology, meaning how they look. There are elliptical, spiral and strangely irregular galaxies, all with different features. Spiral galaxies consist of a central bulge of older stars, a flat rotating disk, and arms spiraling around the disk. Spiral galaxies exist primarily in the nearby universe. As you go out far in distance, back in time, the fewer spirals you see.

Takafumi Tsukui at the university SOKENDAI in Japan is the lead author of the new paper. He said in a statement:

I was excited because I had never seen such clear evidence of a rotating disk, spiral structure, and centralized mass structure in a distant galaxy in any previous literature.

The astronomers used a radio telescope, the Atacama Large Millimetre Array or ALMA telescope, to study galaxy BRI 1335-0417. This observatory located in the Atacama Desert of northern Chile is able to reach a high level of resolution (detail), despite the enormous distance the the galaxy. Tsukui said:

The quality of the ALMA data was so good that I was able to see so much detail that I thought it was a nearby galaxy.

Due to both the galaxys distance, and the early age of the universe at that distance, galaxy BRI 1335-0417 contained a lot of dust that obscures the light from it. The dust makes the galaxy structure hard to see using visible-light telescopes like Hubble. But, at radio wavelengths, astronomers can observe specific elements within the galaxy. And so they can look past the obscuring dust.

In this case, the astronomers looked at the emission from carbon ions for information.

Using the carbon ions as a tool for tracing the galaxys structure, the astronomers could see the spiral shape of BRI 1335-0417. They could see this structure extends about 15,000 light-years from the center of the galaxy. This is about 1/3 of the size of the Milky Way, as a comparison. But BRI 1335-0417 is about as massive as our Milky Way galaxy, including its number of stars and amount of interstellar matter. Just because you dont see it extend farther doesnt mean it isnt larger. Tsuki explained:

As BRI 1335-0417 is a very distant object, we might not be able to see the true edge of the galaxy in this observation. For a galaxy that existed in the early universe, BRI 1335-0417 was giant.

Simulations show that interacting galaxies can form an end-product galaxy with spiral arms. Galaxies interacted much more in the early universe, and so might explain the presence of BRI 1335-0417 so far back in time. There are more clues to that scenario as well: BRI 1335-0417 has a large supply of gas in its outskirts, for example. Thats an indication that theres some kind of supply delivery coming in from the outside, possibly because this galaxy has been colliding with other, smaller galaxies.

The video below is a simulation that shows how many small galaxies interact to form a larger spiral galaxy.

Video 2007 T. Takeda, S. Nukatani, T. R. Saitoh, 4D2U Project, NAOJ.

What happened next is the interesting question. According to conventional theory, star-forming galaxies (like BRI 1335-0417) with lots of dust in the early universe would evolve into giant ellipticals as they age. But maybe that might not happen? Maybe a galaxy like BRI 1335-0417 would remain a spiral for a much longer time? Spirals arms are of special interest to us because, as Tsukui said:

Our solar system lodges in one of the Milky Way spiral arms. Tracing the roots of spiral structure will provide us with clues as to the environment in which the solar system was born. I hope that this research will further advance our understanding of the formation history of galaxies.

Bottom line: Astronomers were surprised to discover spiral arms in a galaxy located in the very early universe. This makes the galaxy, BRI 1335-0417, the most ancient spiral galaxy found so far and provides clues to how and when spiral galaxies formed.

Source: Spiral morphology in an intensely star-forming disk galaxy more than 12 billion years ago

Via ALMA

Theresa Wiegert is a Swedish-Canadian astronomer with a Ph.D. in astrophysics and a master's in physics. She has loved the sky and everything in it and beyond ever since she was four years old and asked her father about the very bright star she saw one early Christmas morning. Learning it wasnt a star but the planet Venus, she started reading anything astronomy-related she could find. Eventually she ended up as a radio astronomer, researching gas in spiral galaxies. She loves science outreach and teaching, especially showing the night sky to groups of kids (and adults!).

Read more from the original source:

The most ancient spiral galaxy yetThe most ancient spiral galaxy yet - EarthSky