By ESA/Hubble
February 27, 2022

A study proves that ground-based telescopes can search for planets with two suns.

Astronomers have used a new technique to confirm a real Tatooine, the fictional planet with two suns that was home to Luke Skywalker in ‘Star Wars’.

The planet, Kepler-16b, is about 245 light-years from Earth, is a gas giant, and is roughly the size of Saturn. Scientists already knew the planet existed, but in a recent study, an international team of astronomers explained how they successfully applied a technique that had never been used before to observe a planet orbiting two stars.

“This is confirmation that our method is working,” said David Martin, co-author of the study and Nasa Sagan Fellow in the Department of Astronomy at Ohio State University. “And that creates an opportunity for us to apply this method now to identify other systems like this.”

The technique, called the radial velocity method, has long been used in astronomy. (The first planet ever found around a sun-like star was found using radial velocity – and was found using the same telescope astronomers used to find this one.)

The method of radial velocities consists of analyzing the spectra of light produced by stars. Astronomers collect spectral data through ground-based telescopes – in this case, from a France-based telescope, the Observatoire de Haute Provence. This spectral data comes in the form of a line, but the line “wobbles” as the planet orbits the two stars, producing a shaky line in the light spectra. The wobble indicates a planet is there, and astronomers can use it to derive a number of other pieces of information about a planet, including its mass.

Measuring radial velocity is, according to Martin, one of the best tools astronomers have for identifying exoplanets, or planets outside our solar system. But until this study, astronomers hadn’t been able to use it to find planets outside our solar system that orbit two stars.

The study was published this week in the Royal Astronomical Society Monthly Notices.

In the past, these planets – called circumbinary planets – were identified by watching the passage of one star in front of another. This method, known as the “transit method,” identified 14 such planets, including Kepler-16b. The first confirmed circumbinary planet was described in a 2011 paper; others followed. But until this article, none had been found using radial velocity.

“What people had to deal with is that having two sets of two star spectra makes it really tricky, and people were having trouble getting enough precision to see the wobble caused by the planet,” Martin said. “And we got around that by doing a survey of systems with two stars orbiting each other where one star is large and the other is quite small.”

The survey, called Binaries Escorted by Orbiting Planets, or BEBOP, was created specifically to search for planets like this.

One of Kepler-16b’s stars is about two-thirds the mass of Earth’s sun, and the other about 20% the mass.

Astronomers had been monitoring this system since July 2016.

Proving that measuring radial velocities can identify planets orbiting two stars, Martin said, opens the door to the technique’s wider application. This is important to astronomers for a number of reasons, but the main one is that planets that orbit two stars tend to exist at a distance that would make them good candidates for life.

“These planets are frequently in the habitable zone, at a distance from stars where one would expect to find liquid water,” Martin said.

Kepler-16b, which is composed mostly of gas, is unlikely to be a candidate where life could be found, Martin said. But using the radial velocity method could help astronomers find other similar planets.

Reference: “BEBOP III. Observations and independent mass measurement of Kepler-16(AB)b – the first circumbinary planet detected with radial velocities” by Amaury HMJ Triaud, Matthew R Standing, Neda Heidari, David V Martin, Isabelle Boisse, Alexandre Santerne, Alexandre CM Correia , Lorena Acuña, Matthew Battley, Xavier Bonfils, Andrés Carmona, Andrew Collier Cameron, Pía Cortés-Zuleta, Georgina Dransfield, Shweta Dalal, Magali Deleuil, Xavier Delfosse, João Faria, Thierry Forveille, Nathan C Hara, Guillaume Hébrard, Sergio Hoyer, Flavien Kiefer, Vedad Kunovac, Pierre FL Maxted, Eder Martioli, Nicola J Miller, Richard P Nelson, Mathilde Poveda, Hanno Rein, Lalitha Sairam, Stéphane Udry and Emma Willett, February 25, 2022, Royal Astronomical Society Monthly Notices.
DOI: 10.1093/mnras/stab3712

Martin’s portion of this work was funded in part by NASA.

Over the past 30 years, the Hubble Space Telescope has helped transform our understanding of the universe. And all the while, it has also regularly quenched the public’s thirst for breathtaking views of nebulae and galaxies dotted across the cosmos.

Known as Arp 282 and located some 300 million light-years away, the galactic duo pictured above, and captured by Hubble, reveals galaxy NGC 169 (bottom) visibly interacting with galaxy IC 1559 ( at the top). In the photo, you can see streaks of gas and dust delicately connecting the two galaxies, the result of the immense tidal forces involved when two gravitational goliaths stray too close.

Although galaxies can often seem isolated, with no close neighbors in sight, that doesn’t mean they always will be. And thanks in part to Hubble images like this, astronomers now know that gaze interactions and head-on collisions between galaxies are fairly common (even though such collisions rarely result in individual star collisions). In fact, close encounters like this play a fundamental role in changing the size, shape, and structure of galaxies over billions of years. Moreover, when two galaxies interact, it can even stir up the gas and dust they contain, triggering new bursts of star formation.

So while galactic collisions, at first glance, may seem like cosmic calamities, in the long run they could actually breathe new life into otherwise darkened and dying island universes.

To discover such an invisible black hole, the team of scientists had to combine two different types of observations over several years.

Our section of the universe has been mapped in the “most accurate simulation yet” by scientists using a supercomputer.

The simulations, which were unveiled at Durham University, capture the Big Bang to the present day and the entire evolution of the cosmos.

The scientists used advanced statistical techniques so that the simulations were conditioned to reproduce our specific part of the universe – thus containing the current structures in the vicinity of our own galaxy.

At the center of the simulation is a pair of galaxies – virtual representations of our own Milky Way and the Andromeda Galaxy.

The research suggests that our local patch of the universe is unusual because the simulation predicted fewer galaxies in an average region of the universe due to large-scale local underdensity of dark matter.

The underdensity could have consequences for how scientists interpret information from studies of observed galaxies – although this is not seen as a challenge to the Standard Model of cosmology.

Dubbed Sibelius-Dark, the new simulation is part of the Simulations Beyond the Local Universe (Sibelius) project and covers a volume up to a distance of 600 million light-years from Earth.

It is also represented by more than 130 billion simulated particles – which require several thousand computers working in tandem for several weeks and producing more than a petabyte of data.

The simulation was performed on the DiRAC COSmology (Cosma) machine operated by the Institute for Computational Cosmology at Durham University.

The researchers involved were made up of people from around the world, including Durham University, and were led by the University of Helsinki.

The research results have been published on arXiv.org and as a preprint in the journal Monthly Notices of the Royal Astronomical Society.

Professor Carlos Frenk, from Durham University’s Institute for Computational Cosmology, said: “It’s hugely exciting to see the familiar structures that we know exist around us emerge from a computer calculation.

“The simulations simply reveal the consequences of the laws of physics acting on dark matter and cosmic gas throughout the 13.7 billion years that our universe has existed.

He added that the ability to reproduce these familiar structures provides “impressive support for the standard model of cold dark matter” and also shows that scientists are on the right track to “understanding the evolution of the entire universe”.

Former Durham PhD student Dr Stuart McAlpine, who is now a postdoctoral researcher at the University of Helsinki, said simulating the universe as we see it means “we are getting closer to understanding the nature of our cosmos”.

He added: “These simulations show that the current main theory of cosmology, the model of cold dark matter, can produce all the galaxies we see in our local habitat, an essential reference for simulations of this type to be successful.

“This project provides an important bridge between decades of astronomical theory and observations.”

The most massive stars in the Universe also have the shortest lifespans. The more mass a star has, the faster it burns up its fuel stores, resulting in lifespans of less than about 10 million years.

This fascinating fact leads us to a riddle. Most of these stars are relatively close to the regions where they were born. But a number of them have been found hidden in strange pockets of the Milky Way, far from the galactic disc where star formation occurs; in other words, their places of birth.

So far, in fact, that the travel time it would have taken to get there far exceeds the lifetimes of many of the stars.

“Astronomers find massive stars far from their place of origin, so far away, in fact, that it takes longer than the lifetime of the star to get there,” said astronomer Douglas Gies of Georgia State University. “How this could happen is a subject of active debate among scientists.”

This absolute idiot of a cosmic pickle, which has long puzzled astronomers, may now have an explanation thanks to new research.

The study focused on a star named HD 93521. It is an O-type star, the most massive star category in the main sequence. HD 93521 is also about 3,600 light-years from the galactic disk, located in a sparsely populated region called the galactic halo. It’s quite a distance, so Gies and his colleagues wanted to know if there was a reasonable way to get there.

They used data from the European Space Agency’s Gaia satellite. This is an ongoing project to map the Milky Way as accurately as possible, in three dimensions and including data on star motions and velocities. They also carefully analyzed the spectrum of light emitted by the star, to help determine its mass, age and rotation.

Data from Gaia revealed that HD 93521 is approximately 4,064 light-years from Earth and the aforementioned 3,600 light-years from the galactic disk.

The team also calculated that the star is around 17 times the mass of the Sun, with an average temperature of around 30,000 Kelvin. At this mass and temperature, the star should be about 5 million years old, with a margin of error of about 2 million years. Its maximum lifespan is about 8.3 million years.

However, migrating from its birthplace in the galactic disk to its current location would take a journey of approximately 39 million years.

It’s a real headache, but the star herself could hold the key to the mystery. The rate of rotation of our Sun is just under 2 kilometers (1.24 miles) per second. The HD 93521 rotates at an absolute speed of 435 kilometers (270 miles) per second.

There are several mechanisms that can increase a star’s rotational speed. One of the most important effects would be a stellar merger, which would not only combine the spins of the two stars, but also the angular momentum of their orbits.

That’s what the team thinks happened with HD 93521. It started life as a binary made up of two medium-mass stars, which merged to form the star as we see it today. in the relatively recent past.

These medium-mass stars would be long enough to survive the trip through the galactic halo, the researchers said.

They even found a binary that could validate their discovery. Another star system IT Librae is a binary composed of two B-type stars (one step smaller than O-type stars), one of which is more massive than the other.

This larger star also appears to have too short a lifespan for the travel time it would have taken to reach its current position. But in a paper currently in press, a team of researchers explain that the two stars are in close binary, and that the smaller one has already started to transfer mass to the larger one.

This means that the current mass of the largest is misleading; because it started out smaller, its lifespan is probably longer than it currently looks.

“The observed properties of HD 93521 all appear to be in line with expectations for a fusion product. The star appears to be too young relative to its flight time from the galactic disk as it has been rejuvenated through stellar fusion of binary components “, said the researchers wrote.

“Investigations of such systems will provide important clues to the properties of post-mass transfer and fusion systems that are essential to understanding their ultimate supernova progeny.”

The research has been published in The Astronomical Journal.

NASA took to their blog to explain that the Hubble Space Telescope was used to observe a region of space called the Chamaeleon Cloud Complex.

SEE THE GALLERY – 2 IMAGES

The Chamaeleon Cloud Complex is a star forming region that spans 65 light years across. The photograph above is a composite image called Chamaeleon Cloud I (Cha I), and it features the reflection nebulae shining with the light of young blue stars. Additionally, the dark, dusty clouds seen in the image are regions of space where stars are forming. Radiating nodes are also visible throughout the image. These are called Herbig-Haro objects.

NASA explains:Herbig-Haro objects are bright tufts and arcs of interstellar gas shocked and energized by jets expelled from infant “protostars” in the process of formation. The white-orange cloud at the bottom of the image hosts one of these protostars at its center. Its bright white jets of hot gas are ejected in narrow torrents from the poles of the protostar, creating Herbig-Haro object HH ​​909A.“

The space agency writes that Cha 1 was observed with the intention of locating low-mass brown dwarf stars. NASA describes these stars as “lack“due to their lack of mass preventing them from igniting to maintain nuclear fusion in their cores.”Hubble research has found six new low-mass brown dwarf candidates that help astronomers better understand these objects.“

For more information on this story, see this link here.

Jak Connor

Jak joined the TweakTown team in 2017 and has since reviewed hundreds of new tech products and kept us up to date with the latest science and space news daily. Jak’s love of science, space and technology, and specifically PC gaming, began when he was 10 years old. It was the day his father showed him how to play Age of Empires on an old Compaq PC. From that day on, Jak fell in love with games and the advancement of the tech industry in all its forms. Instead of a typical FPS, Jak holds a very special place in his heart for RTS games.

About 13.8 billion years ago, our Universe was born from a massive explosion that gave rise to the first subatomic particles and the laws of physics as we know them. About 370,000 years later hydrogen had formed, the building block of stars, which fuse the hydrogen and helium within them to create all of the heavier elements. Although hydrogen remains the most common element in the Universe, it can be difficult to detect individual clouds of hydrogen gas in the interstellar medium (ISM).

This makes it difficult to find the earliest phases of star formation, which would offer clues to the evolution of galaxies and the cosmos. An international team led by astronomers from the Max Planck Institute for Astronomy (MPIA) recently noticed a massive filament of atomic hydrogen gas in our galaxy. This structure, named “Maggie”, is located about 55,000 light-years away (on the other side of the Milky Way) and is one of the longest structures ever observed in our galaxy.

The study that describes their findings, recently published in the journal Astronomy & Astrophysics, was led by Jonas Syed, a Ph.D. student at the MPIA. He was joined by researchers from the University of Vienna, the Harvard-Smithsonian Center for Astrophysics (CFA), Max Planck Institute for Radio Astronomy (MPIFR), University of Calgary, Universität Heidelberg, Center for Astrophysics and Planetary Science, Argelander-Institute for Astronomy, Indian Institute of Science, and Nasa‘s Jet Propulsion Laboratory (JPL).

The research is based on data obtained from the Milky Way HI/OH/Recombination Line Study (THOR), an observing program that relies on the Karl G. Jansky Very Large Array (VLA) at the New Mexico. Using the VLA’s centimetre-wave radio dishes, this project studies molecular cloud formation, the conversion of atomic hydrogen to molecular hydrogen, the magnetic field of the galaxy, and other questions related to ISM and to star formation.

The ultimate goal is to determine how the two most common hydrogen isotopes converge to create dense clouds that rise to new stars. Isotopes include atomic hydrogen (H), consisting of one proton, one electron, and no neutrons, and molecular hydrogen (H₂) is composed of two hydrogen atoms linked by a covalent bond. Only the latter condenses into relatively compact clouds that will develop frosty regions where new stars eventually emerge.

This image shows a section of the side view of the Milky Way as measured by ESA’s Gaia satellite. The dark band is made up of gas and dust, which attenuates the light from the embedded stars. The galactic center of the Milky Way is shown on the right of the image, glowing below the dark area. The box to the left of the middle marks the location of the “Maggie” filament. It shows the distribution of atomic hydrogen. The colors indicate different gas velocities. Credit: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO & T. Müller/J. Syed/MPIA

The transition process from atomic hydrogen to molecular hydrogen is still largely unknown, which made this extraordinarily long filament a particularly exciting discovery. While the largest known clouds of molecular gas are typically around 800 light-years in length, Maggie is 3,900 light-years long and 130 light-years wide. As Syed explained in a recent MPIA press release:

“The location of this filament contributed to this success. We don’t yet know exactly how it got there. But the filament extends about 1600 light-years below the plane of the Milky Way. The observations also allowed us to determine the velocity of hydrogen gas. This allowed us to show that the velocities along the filament hardly differ.”

The team’s analysis showed that the material in the filament had an average speed of 54 km/s^-1, which they determined primarily by measuring it relative to the rotation of the Milky Way’s disk. This meant that radiation at a wavelength of 21 cm (aka the “hydrogen line”) was visible against the cosmic background, making the structure discernible. “The observations also allowed us to determine the velocity of hydrogen gas,” said Henrik Beuther, director of THOR and co-author of the study. “This allowed us to show that the velocities along the filament hardly differ.”

This false color image shows the distribution of atomic hydrogen measured at a wavelength of 21 cm. The red dotted line traces the “Maggie” filament. Credit: J. Syed/MPIA

From there, the researchers concluded that Maggie is a coherent structure. These findings confirmed observations made a year earlier by Juan D. Soler, an astrophysicist at the University of Vienna and co-author of the paper. When he observed the filament, he gave it the name of the longest river in his native Colombia: the Río Magdalena (anglicized: Margaret, or “Maggie”). While Maggie was recognizable in Soler’s earlier assessment of THOR data, only the current study proves beyond doubt that it is a consistent structure.

Based on previously published data, the team also estimated that Maggie contains 8% molecular hydrogen by mass fraction. Upon closer inspection, the team noticed that the gas converges at various points along the filament, leading them to conclude that the hydrogen gas collects in large clouds at these locations. They further speculate that atomic gas will gradually condense into a molecular form in these environments.

“However, many questions remain unanswered,” Syed added. “Additional data, which we hope will give us more clues about the molecular gas fraction, is already waiting to be analyzed.” Fortunately, several space and ground observatories will soon be operational, telescopes that will be equipped to study these filaments in the future. These include the James Webb Space Telescope (JWST) and radio soundings like the Square Kilometer Array (SKA), which will allow us to visualize the very first period of the Universe (“Cosmic Dawn”) and the first stars of our Universe.

Originally published on Universe Today.

For more on this research, see Massive Filament Structure – 3900 Light-Years Long – Discovered in the Milky Way.

Reference: “The “Maggie” filament: physical properties of a giant atomic cloud” by J. Syed, JD Soler, H. Beuther, Y. Wang, S. Suri, JD Henshaw, M. Riener, S. Bialy, S 20 December 2021, Astronomy & Astrophysics.
DOI: 10.1051/0004-6361/202141265

As stars begin to reach the end of their life cycle, they get bigger. Surrounding planets lose their orbital energy and move closer together, eventually being consumed by the star.

The Earth will eventually be swallowed up by the Sun, but that won’t happen for at least five billion years. The Sun is estimated to be about halfway through its life cycle.

Astronomers at the University of Hawaii have discovered three planets about to be absorbed by stars similar in mass to our Sun. They were detected using NASA’s Transiting Exoplanet Survey Satellite (TESS) space telescope.

“The changes we expect to see for the Sun are the same as we see in these different solar systems where the radius of the star increases, the star swells and cools, but the radius will increase so dramatically that we we expect the inner planets of the solar system to actually be consumed by the surface of the Sun itself,” said Nick Saunders, a UH graduate student working on the project.

“So as the radius of the Sun moves away, the inner planets out to the vicinity of Earth will likely be inside the star at that time,” Saunders said.

The three observed planets (TOI-2337b, TOI-4329b, TOI-2669b) are less than 2,000 light-years from Earth.

The planet labeled TOI-2337b will be swallowed up by its star in less than a million years. Of all the currently observable planets, this one will be consumed by a star the earliest.

A group of astronomers and citizen scientists have discovered a hidden planet the size of Jupiter in a distant solar system, and they should be lucky enough to see it again soon.

The planet, designated TOI-2180 b, is relatively close to us here on Earth, just 379 light-years away. But what makes this world special among the sample of known giant exoplanets is that it takes 261 days to orbit its host star, far longer than most gas giants discovered outside our solar neighborhood. .