Universe Today

March 16, 2021March 16, 2021 by Ralph Crewe

Do Supermassive Black Holes Come From Supermassive Stars?

Colors reveal complex interactions of oxygen abundance driving a supernova in a 55,000 solar mass star.

The gargantuan supermassive black holes at the center of seemingly every galaxy are among the most fascinating and extreme objects known to modern astronomy and cosmology. With masses well in excess of millions, and sometimes billions that of our Sun, it is nearly impossible to comprehend the extraordinary size of these celestial leviathans. One of the great mysteries of modern astrophysics is answering how such enormous objects got started. In a press release published on March 10th, researchers propose that the origins of supermassive black holes may lie with long since extinct, first-generation stars with masses far above the most massive stars in the modern Universe. Not only do they propose such giants existed, but also they suggest that they’ve found a way to detect a particular subset of these stars. This breakthrough is thanks to our old friend, Einstein’s General Theory of Relativity.

March 15, 2021March 15, 2021 by Brian Koberlein

Wormholes Could Allow Travel Across the Universe, as Long as Your Spacecraft is Microscopic

Artist rendering of a wormhole connecting two galaxies. Credit: Davide and Paolo Salucci

In my last post, I talked about the idea of warp drive and whether it might one day be possible. Today I’ll talk about another faster-than-light trick: wormholes.

March 14, 2021March 14, 2021 by Matt Williams

There Should be About 7 Interstellar Objects Passing Through the Inner Solar System Every Year

A Hubble image of Comet 2IBorisov from October 2019. Image Credit: By NASA, ESA, and D. Jewitt (UCLA) - https://imgsrc.hubblesite.org/hvi/uploads/image_file/image_attachment/31897/STSCI-H-p1953a-f-1106x1106.png, Public Domain, https://commons.wikimedia.org/w/index.php?curid=83146132

In October 19th, 2017, the first interstellar object ever detected flew past Earth on its way out of the Solar System. Less than two years later, a second object was detected, an easily-identified interstellar comet designated as 2I/Borisov. The appearance of these two objects verified earlier theoretical work that concluded that interstellar objects (ISOs) regularly enter our Solar System.

The question of how often this happens has been the subject of considerable research since then. According to a new study led by researchers from the Initiative for Interstellar Studies (i4is), roughly 7 ISOs enter our Solar System every year and follow predictable orbits while they are here. This research could allow us to send a spacecraft to rendezvous with one of these objects in the near future.

March 12, 2021March 12, 2021 by Ralph Crewe

A Planet Lost Its Atmosphere, So Its Volcanoes Made It a New One

Credit: NASA, ESA, and R. Hurt (IPAC/Caltech)

A red-dwarf star called Gliese 1132 or GJ 1132 for short (astronomers and their fun nicknames!) smolders on some 41 light-years from the sun in the southern constellation Vela, just a few degrees away from the southern cross. In 2015, astronomers using the MEarth South telescope array at Cerro Tololo Inter-American Observatory (CTIO) in Chile found an Earth-sized planet orbiting extremely close to the little red star. Known as GJ 1132b, the planet orbits in a blistering 1.6 days. Its original hydrogen and helium atmosphere is thought to have long since been blown away by the powerful stellar winds experienced by the planet due to its extreme proximity to its parent. New observations from the Hubble Space Telescope revealed a surprise from the speedy exoplanet; it seems to have re-formed an atmosphere!

March 12, 2021March 12, 2021 by Matt Williams

The Giant Magellan Telescope’s 6th Mirror has Just Been Cast. One More to Go

By 2029, the Giant Magellan Telescope (GMT) in northern Chile will begin collecting its first light from the cosmos. As part of a new class of next-generation instruments known as “extremely large telescopes” (ELTs), the GMT will combine the power of sophisticated primary mirrors, flexible secondary mirrors, adaptive optics (AOs), and spectrometers to see further and with greater detail than any optical telescopes that came before.

At the heart of the telescope are seven monolithic mirror segments, each measuring 8.4 m (27.6 ft) in diameter, which will give it the resolving power of a 24.5 m (80.4 ft) primary mirror. According to recent statements from the GMT Organization (GMTO), the University of Arizona’s Richard F. Caris Mirror Lab began casting the sixth and seventh segments for the telescope’s primary mirror (which will take the next four years to complete).

March 12, 2021March 12, 2021 by Scott Alan Johnston

China and Russia Will Be Partners in a Lunar Research Station

There are many paths to the Moon, and not all of them go through the Lunar Gateway. This week, the heads of the Russian Space Agency (Roscosmos) and the China National Space Administration (CNSA) signed an agreement to cooperate on a Lunar research station of their own.

March 12, 2021March 12, 2021 by Brian Koberlein

Alcubierre Gives us an Update on his Ideas About Warp Drives

The Enterprise using warp drive, as seen in Star Trek Beyond. Credit: Paramount Pictures

If you want a galaxy-spanning science fiction epic, you’re going to need faster than light travel. The alternative is taking decades or centuries to reach an alien star system, which isn’t nearly as much fun. So, you start with some wild scientific idea, add a bit of technobabble, and poof! Quam Celerrime ad Astra. Everything from wormholes to hyperspace has been used in sci-fi, but perhaps the best known FTL trope is warp drive.

March 12, 2021March 9, 2021 by Paul M. Sutter

Measuring the Temperatures of Red Giants is Actually Pretty Tricky

Artist's impression of a red giant star. If the star is in a binary pair, what happens to its sibling? Credit:NASA/ Walt Feimer

Red giant stars are, well, red and giant. But astronomers have always had difficulty estimating their temperatures, due to their complex and turbulent atmospheres. Without an accurate gauge of their temperatures, it’s difficult to tell when they will end their lives in gigantic supernova explosions. Now a team of astronomers have developed a more effective technique for taking the temperature of red giants, based on the amount of iron in the stars.

March 12, 2021March 9, 2021 by Paul M. Sutter

Comets Already Grow a Coma out in the Kuiper Belt

NAVCAM image of comet 67P/Churyumov-Gerasimenko acquired on Nov. 22, 2015.

Just when do comets get their signature coma? Conventional wisdom says it only happens when they get close enough to the sun, but new research suggests it starts when they are still beyond the orbit of the planets.

March 11, 2021March 9, 2021 by Paul M. Sutter

The Oldest Stars Help Tell us how big the Universe is

Artist’s impression of the star in its multi-million year long and previously unobservable phase as a large, red supergiant. Credit: CAASTRO / Mats Björklund (Magipics)

Astronomers are struggling to understand the discrepancies when measuring the expansion rate of the universe with different methods, and are desperate for any creative idea to break the tension. A new method involving some of the oldest stars in the universe could just do the trick.