Astronomers Finally Catch a Nova Detonating on a White Dwarf as it's Happening

Artist impression of an exploding White Dwarf. Credit: University of Tubigen.

On July 7, 2020, the X-ray instrument eROSITA captured an astronomical event that – until then – had only been theorized and never seen. It saw the detonation of a nova on a white dwarf star, which produced a so-called fireball explosion of X-rays.

“It was to some extent a fortunate coincidence, really,” said Ole König from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), who led the team of scientists who have published a new paper on the discovery. “These X-ray flashes last only a few hours and are almost impossible to predict, but the observational instrument must be pointed directly at the explosion at exactly the right time.”

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This is it! Meet the Supermassive Black Hole at the Heart of the Milky Way

This is the first image of Sgr A*, the supermassive black hole at the center of our galaxy. A reanalysis of EHT data by NAOJ scientist suggests its accretion disk may be more elongated than shown in this image. Image Credit: EHT
This is the first image of Sgr A*, the supermassive black hole at the center of our galaxy. A reanalysis of EHT data by NAOJ scientist suggests its accretion disk may be more elongated than shown in this image. Image Credit: EHT

On April 10th, 2019, the international consortium known as the Event Horizon Telescope (EHT) announced the first-ever image of a supermassive black hole (SMBH). The image showed the bright disk surrounding the black hole at the center of the M87 galaxy (aka. Virgo A). In 2021, they followed up on this by acquiring an image of the core region of the Centaurus A galaxy and the radio jet emanating from it. Earlier this month, the European Southern Observatory (ESO) announced that the EHT would be sharing the results from its latest campaign – observations of Sagittarius A*!

This supermassive black hole resides at the center of the Milky Way Galaxy, roughly 27,000 light-years from Earth, 44 million km (27.34 million mi) in diameter, and has a mass of 4.31 million Suns. The campaign’s results were shared in an ESO press release and a series of live-streamed press conferences worldwide, including the ESO Headquarters in Munich, Germany. The team’s results (which were shared in six papers) were also published today in a special issue of The Astrophysical Journal Letters.

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We’ve Now Seen Planet-Forming Disks Around Hundreds of Young Stars. What Do They Tell Us?

ALMA's high-resolution images of nearby protoplanetary disks, which are results of the Disk Substructures at High Angular Resolution Project (DSHARP). The observatory is often used to look for planet birth clouds like these and the one around HD 169142. Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello
ALMA's high-resolution images of nearby protoplanetary disks, which are results of the Disk Substructures at High Angular Resolution Project (DSHARP). The observatory is often used to look for planet birth clouds like these and the one around HD 169142. Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello

Is our Solar System comparable to other solar systems? What do other systems look like? We know from exoplanet studies that many other systems have hot Jupiters, massive gas giants that orbit extremely close to their stars. Is that normal, and our Solar System is the outlier?

One way of addressing these questions is to study the planet-forming disks around young stars to see how they evolve. But studying a large sample of these systems is the only way to get an answer. So that’s what a group of astronomers did when they surveyed 873 protoplanetary disks.

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Our Complete Guide to This Weekend’s Total Lunar Eclipse

Becke eclipse
A mosaic of the # total lunar eclipse. Image credit and copyright: Christopher Becke.

Don’t miss one of the top astronomical events for 2022: Sunday night’s total lunar eclipse.

The first eclipse season of 2022 reaches its climax this coming weekend, with a fine total lunar eclipse transpiring on Sunday night into Monday morning. All of South America and most of North America will see the eclipse in its entirety, while Alaska and western Canada will see totality underway at moonrise, and western Europe will see the reverse at moonset near dawn.

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China Announces Its New Flagship Space Telescope Mission

Artist's concept of Chinese Space Station Telescope (CSST).  Credit: Jaimito130805, CC BY-SA 4.0
Artist’s concept of the Chinese Space Station Telescope (CSST). Credit: Jaimito130805, CC BY-SA 4.0

Distant galaxies, dark matter, dark energy, and the origin and evolution of the universe itself are some of the many scientific goals of China’s newly announced space telescope. If all goes according to plan, the China Space Station Telescope (CSST) will blast off atop a Long March 5B rocket sometime in late 2023. Once in a safe orbit, CSST should begin observations in 2024. Judging by these research topics, it looks like the Chinese Academy of Sciences is throwing down an impressive scientific gauntlet for itself and its astronomers.

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We can Probably Find Supernovae Enhanced by Gravitational Lensing, We Just Need to Look

Using the microlensing metthod, a team of astrophysicists have found the first extra-galactic planets! Credit: NASA/Tim Pyle

Gravitational lensing provides an opportunity to see supernovae and other transients much farther than we normally can. A new research proposal outlines a plan to use a comprehensive catalog of strong gravitational lenses to capture these rare events at extreme distances.

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Even Stars Doomed to Die as Supernovae can Have Planets

90 percent of all exoplanets discovered to date (there are now more than 5000 of them) orbit around stars the same size or smaller than our sun. Giant stars seem to lack planetary companions, and this fact has serious implications for how we understand solar system formation. But is the dearth of planets around large stars a true reflection of nature, or is there some bias inherent in how we look for exoplanets that is causing us to miss them? The recent discovery of two gas giants orbiting a giant star called µ2 Scorpii suggests it might be the latter.

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What Does Micrometeoroid Damage do to Gossamer Structures Like Webb’s Sunshield?

Sunshield test unit on NASA's James Webb Space Telescope is unfurled for the first time at Northrup Grumman. Credit: NASA

Tiny little bullets flood the solar system, each micrometeoroid a potential hazard. New research has found that the James Webb Space Telescope’s thin sunshields, and future inflatable spacecraft, may be at risk.

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A Giant Galaxy has been Unwinding its Neighbor for 400 Million Years

The interacting galaxy pair NGC 1512 and NGC 1510 take center stage in this image from the Dark Energy Camera, a state-of-the art wide-field imager on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory
The interacting galaxy pair NGC 1512 and NGC 1510 take center stage in this image from the Dark Energy Camera, a state-of-the art wide-field imager on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory. Courtesy NOIRLab.

Sometimes you have to just sit back and marvel at a particularly gorgeous view of a galaxy interaction. When these giant space cities merge with each other, wild and crazy things happen—a sort of “Galaxies Gone Wild” scenario. Take this pair, for example. We see them locked together in a cosmic dance that has lasted for not quite a half-billion years. With each turn on the intergalactic dance floor, they change each other permanently. Eventually, they’ll combine to make one giant galaxy.

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