Universe Today

February 17, 2023February 17, 2023 by Brian Koberlein

When Neutron Stars Collide, the Explosion is Perfectly Spherical

This artist’s impression shows two tiny but very dense neutron stars at the point at which they merge and explode as a kilonova. Such a very rare event is expected to produce both gravitational waves and a short gamma-ray burst, both of which were observed on 17 August 2017 by LIGO–Virgo and Fermi/INTEGRAL respectively. Subsequent detailed observations with many ESO telescopes confirmed that this object, seen in the galaxy NGC 4993 about 130 million light-years from the Earth, is indeed a kilonova. Such objects are the main source of very heavy chemical elements, such as gold and platinum, in the Universe.

Kilonovae are incredibly powerful explosions. Whereas regular supernovae occur when two white dwarfs collide, or the core of a massive star collapses into a neutron star, kilonovae occur when two neutron stars collide. You would think that neutron star collisions would produce explosions with all sorts of strange shapes depending on the angle and speed of the collisions, but new research shows kilonovae are very spherical, and this has some serious implications for cosmology.

February 16, 2023February 16, 2023 by Evan Gough

What Would Happen if the Solar System Gained a Super-Earth?

This illustration shows the super-Earth exoplanet 55 Cancri e with its star. What would our Solar System be like if it was home to a super-Earth like this one? Credit: NASA/JPL

In this era of exoplanet discovery, astronomers have found over 5,000 confirmed exoplanets, with thousands more awaiting confirmation and many billions more waiting to be discovered. These exoplanets exist in a bewildering spectrum of sizes, compositions, orbital periods, and just about every other characteristic that can be measured.

Learning about them has also shed light on our Solar System. We used to think of it as an archetypal arrangement of planets since it’s all we had to go on. But now we know we might be the outlier because we have no Super-Earth.

February 16, 2023February 16, 2023 by Andy Tomaswick

The Mass of a Single Star (other than the Sun) has Been Directly Measured for the First Time

How do you measure an object’s weight from a distance? You could guess at its distance and therefore derive its size. Maybe you could further speculate about its density, which would eventually lead to an estimated weight. But these are far from the exact empirical studies that astrophysicists would like to have when trying to understand the weight of stars. Now, for the first time ever, scientists have empirically discovered the weight of a distant single star, and they did so using gravitational lensing.

February 16, 2023February 16, 2023 by Matt Williams

Webb Sees Three Galaxy Clusters Coming Together to Form a Megacluster

Pandora's Cluster, imaged by the UNCOVER project using the JWST. Credit: Credits: NASA/ESA/CSA, I. Labbe/R. Bezanson/ Alyssa Pagan (STScI)

As the successor to the venerable Hubble Space Telescope, one of the main duties of the James Webb Space Telescope has been to take deep-field images of iconic cosmic objects and structures. The JWST’s next-generation instruments and improved resolution provide breathtakingly detailed images, allowing astronomers to learn more about the cosmos and the laws that govern it. The latest JWST deep-field is of a region of space known as Abell 7244 – aka. Pandora’s Cluster – where three galaxy clusters are in the process of coming together to form a megacluster.

February 15, 2023February 15, 2023 by Matt Williams

Another Russian Spacecraft is Leaking Coolant

The Soyuz MS-22 crew ship approaches the space station above the Mediterranean Sea with three new crew members for a docking to the Rassvet module. Credit: NASA

Roscosmos appears to be having some issues with a spacecraft again. In December, the Soyuz MS-22 spacecraft that delivered three crewmembers of Expedition 68 to the International Space Station (ISS) reported a leak in its coolant loop. On February 11th, engineers at the Russian Mission Control Center outside Moscow recorded a depressurization in Progress 82, an uncrewed cargo craft docked with the Poisk laboratory module. The cause of these leaks remains unknown, but Roscosmos engineers (with support from their NASA counterparts) will continue investigating.

February 15, 2023February 15, 2023 by Carolyn Collins Petersen

The Event Horizon Telescope Gazes into the Heart of a Distant Quasar

an artistic concept of a quasar — Concept image of a galactic quasar. Astronomers used the Event Horizon Telescope to study details at the heart of one like this called NRAO 530. Credit: ParallelVision, Pixabay

Oftentimes in astronomy, it takes a village of telescopes and people to make an amazing find. In the case of the quasar NRAO 530, it took a planet full of radio dishes ganged together to peer into its heart. Then, it took a major collaboration of scientists to figure out what the instruments were telling them.

February 15, 2023February 15, 2023 by Matt Williams

Ingenuity is Doing Surprisingly Well

Sol 650 Z-Cam image inadvertently catches the solitary Mars helicopter as it struggles to stay warm Credits: NASA/JPL-Caltech/ASU/MSSS

Exploring Mars is hazardous work. Robotic missions that are sent there have to contend with extreme temperatures, dust storms, intermittent sunlight, and rough terrain. In recent years, two robotic missions were lost due to dust alone, and all that roving around has done a number on the Curiosity rover’s treads. It’s understandable why mission teams are pleasantly surprised when their missions make it through a rough patch. This was the case with the Ingenuity team when they discovered that the rotorcraft, which has been exploring Mars alongside Perseverance, survived the night and is back in working order.

Testing how robotic helicopters fair in the Martian environment is one of the objectives of Ingenuity, which is the first mission of its kind on Mars. On May 3rd, 2022, the mission team learned that Ingenuity had lost power after trying to keep itself warm during the cold Martian night. Luckily, there was enough sunlight the following morning for the little rotorcraft to power up its batteries again and resume normal operations. This was a welcome relief, given that the Opportunity rover and InSight lander were both lost to the extreme cold and dust that characterize a Martian winter.

February 15, 2023February 15, 2023 by Evan Gough

A Galaxy has Been Found that’s Almost Entirely Dark Matter

This is the galaxy Dragonfly 44, which is an Ultra Diffuse Galaxy (UDG.) It's about as massive as the Milky Way, but only 1% as luminous. Astronomers think it's almost entirely made of dark matter. Now scientists have found another one like it. Image Credit: By Teymursaif - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=95121595

Astronomers have discovered a galaxy with very little or no stellar mass. Galaxies like these are called ‘dark galaxies.’ It contains clouds of gas but very few stars, possibly none. This is the only isolated dark dwarf galaxy in the local universe.

February 15, 2023February 15, 2023 by Evan Gough

Perseverance is Building Up a Big Collection of Mars Samples

This photomontage shows each of the sample tubes shortly after they were deposited onto the surface by NASA's Perseverance Mars rover, as viewed by the WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera on the end of the rover's 7-foot-long (2-meter-long) robotic arm. Image Credit: NASA/JPL-Caltech/MSSS

NASA’s Perseverance Rover has reached another milestone. It’s finished caching its samples for a potential return to Earth. The sample depot is located in Mars’ Jezero Crater, where Perseverance is busy searching for signs of ancient life.

February 15, 2023February 15, 2023 by Laurence Tognetti

Magnetars are Extreme in Every Way, Even Their Volcanoes

Artist rendition of a magnetar eruption. These could be source of fast radio bursts. (Credit: NASA Goddard Space Flight Center)

In a recent study published in Nature Astronomy, an international team of researchers led by NASA and The George Washington University examined data from an October 2020 detection of what’s known as a “large spin-down glitch event”, also known as an “anti-glitch”, from a type of neutron star known as a magnetar called SGR 1935+2154 and located approximately 30,000 light-years from Earth, with SGR standing for soft gamma repeaters. Such events occur when the magnetar experiences a sudden decrease in its rotation rate, which in this case was followed by three types of radio bursts known as extragalactic fast radio bursts (FRBs) and then pulsed radio emissions for one month straight after the initial rotation rate decrease.