Astronomy Archives

December 8, 2021February 17, 2023 by Matt Williams

A Nearby Dwarf Galaxy has a Surprisingly Massive Black Hole in its Heart

Since the 1970s, scientists have known that within the cores of most massive galaxies in the Universe, there beats the heart of a Supermassive Black Hole (SMBH). The presence of these giant black holes causes these galaxies to be particularly energetic, to the point where their central regions outshine all the stars in their disks combined – aka. Active Galactic Nuclei (AGN). The Milky Way galaxy has its own SMBH, known as Sagittarius A*, which has a mass of over 4 million Suns.

For decades, scientists have studied these objects in the hopes of learning more about their role in galactic formation and evolution. However, current research has shown that SMBHs may not be restricted to massive galaxies. In fact, a team of astronomers from the University of Texas at Austin’s McDonald Observatory recently discovered a massive black hole at the heart of a dwarf galaxy that orbits the Milky Way (Leo I). This finding could redefine our understanding of how black holes and galaxies evolve together.

December 8, 2021December 8, 2021 by Evan Gough

TESS Finds a New Mars-Sized Planet (With the Density of Mercury)

An artist's illustration of a hypothetical exoplanet orbiting a red dwarf. Image Credit: NASA/ESA/G. Bacon (STScI)

Some planets orbit their stars so closely that they have extremely high surface temperatures and extremely rapid orbits. Most of the ones astronomers have found are Hot Jupiters— planets in the size range of Jupiter and with similar compositions as Jupiter. Their size and proximity to their star make them easier to spot using the transit method.

But there’s another type of planet that also orbits very close to their stars and has extremely high surface temperatures. They’re small, rocky, and they orbit their star in less than 24 hours. They’re called ultra-short-period (USP) planets and TESS found one that orbits its star in only eight hours.

And the planet’s density is almost equivalent to pure iron.

December 8, 2021December 8, 2021 by Matthew Cimone

A New Way to Detect Alien Megastructures

Dyson Sphere as Depicted in the videogame "Stellaris", developed and published by Paradox Interactive. Used with permission. Screenshot by author

How do you power a super advanced alien civilization? Soak up a star. We harness the power of the Sun using solar panels. What if you were to scale this idea to astronomical proportions? Surround an entire star with solar collecting structures or satellites to power your sprawling alien galactic empire. Such massive structures are known as a “megastructures” – in this case a “Dyson Sphere.” We are already trying to detect possible megastructures in space using the dimming of a star and the glow of megastructure components in infrared light. But recent research provides a new detection method – a Dyson Sphere may cause its host star to swell and cool.

December 7, 2021December 7, 2021 by Evan Gough

Giant Stars and the Ultimate Fate of the Sun

Sizes of giant stars relative to our Sun. Going from the G-type to K-type to M-types, giant stars get progressively redder (cooler) and larger. Late M-type giants are more than 100 times the size of our Sun. Image Credit: Lowell Observatory.

Astronomers have a new tool to help them understand giant stars. It’s a detailed study of the precise temperatures and sizes of 191 giant stars. The authors of the work say that it’ll serve as a standard reference on giant stars for years to come.

It’ll also shed some light on what the Sun will go through late in its life.

December 7, 2021December 7, 2021 by Evan Gough

Asteroid Apophis’ 2029 Flyby Will Provide a Bonanza of Asteroid Science

The asteroid 99942 Apophis. Image Credit: NASA/Caltech/JPL

If NASA and other space agencies don’t want us to freak out about asteroids colliding with Earth, why do they give them names like Apophis? It sounds apocalyptic.

Apophis was the ancient Egyptian god of Chaos. He was an evil serpent that dwelled in endless darkness, the enemy of light and truth. So when they informed us that an asteroid named Apophis was due for a close encounter with Earth in 2029, people were understandably anxious. After all, Earth’s previous dominant inhabitants were evicted by an asteroid.

December 6, 2021January 11, 2022 by Tammy Plotner

Messier 95 – the NGC 3351 Barred Spiral Galaxy

Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the barred spiral galaxy known as Messier 95!

During the 18th century, famed French astronomer Charles Messier noticed the presence of several “nebulous objects” while surveying the night sky. Originally mistaking these objects for comets, he began to catalog them so that others would not make the same mistake. Today, the resulting list (known as the Messier Catalog) includes over 100 objects and is one of the most influential catalogs of Deep Space Objects.

One of these objects is Messier 95 (aka. NGC 3351), a barred spiral galaxy located about 33 million light-years away. Measuring over 80,000 light-years, or 24.58 kiloparsecs (kpc) in diameter, this galaxy is one of several that fall into the M96 Group, located in the constellation Leo. This Group consists of between 8 and 24 galaxies in total and three Messier Objects: M95, M96, and M105.

December 6, 2021March 7, 2022 by Alan Boyle

‘Don’t Look Up’ Shines a Satirical Spotlight on Campaign to Counter Cosmic Threats

Scene from "Don't Look Up" with Jennifer Lawrence and Leonardo DiCaprio — Jennifer Lawrence and Leonardo DiCaprio portray scientists who find a killer comet in "Don't Look Up." (Netflix Photo / Niko Tavernise)

The science adviser for “Don’t Look Up,” a star-studded comedy about a killer comet, has some serious advice for dodging a threat from the skies: Take the title of the movie, and do the exact opposite.

“The sensible thing to do about this particular problem is … just go look up and see if it’s out there,” said Amy Mainzer, a planetary scientist at the University of Arizona’s Lunar and Planetary Laboratory. “And do a thorough enough job of it that we have a reasonable chance of spotting something that’s large enough to cause appreciable damage, well before it could make its way here.”

The roughly 5-mile-wide comet that’s heading for Earth in “Don’t Look Up,” with only about six and a half months of advance warning, is totally fictional. Nevertheless, the movie is a teachable moment for the science surrounding asteroids, comets and planetary defense. And Mainzer said the stars of the show, including Leonardo DiCaprio and Jennifer Lawrence, were unusually eager students.

“These actors wanted to know everything,” she said. “I would say they’re approaching some pretty solid knowledge of just how do we find asteroids and comets, and what do we do about them.”

Mainzer discusses what’s going on with the search for potentially threatening near-Earth objects, as well as her experience as a science adviser for “Don’t Look Up,” in the latest episode of the Fiction Science podcast, coming to you from the place where science and technology intersect with fiction and popular culture.

December 6, 2021December 6, 2021 by Matt Williams

Colliding Gases at the Heart of the Running Man Nebula

Behold, the Herbig-Haro object known as HH45, captured by the Hubble Space Telescope (HST)! These objects are a rarely seen type of nebula made up of luminous clouds of dust and gas. These occur when newborn stars form within a nebula and eject hot gas, colliding with the surrounding gas and dust. The result is bright shock waves that look like mounded, luminous clouds in space!

December 5, 2021December 5, 2021 by Scott Alan Johnston

If There are Water Plumes on Europa, Here’s how Europa Clipper Will Study Them

NASA’s Europa Clipper is one of the most anticipated missions of the coming decade, in large part because its target, the large Jovian moon Europa, is considered one of the most likely places in our solar system that extraterrestrial life might exist. If Europa is harboring alien microbes, however, they’re likely to be buried deep beneath the moon’s thick icy crust in a vast subsurface ocean. Unlocking the secrets of this water world isn’t going to be easy, but the Clipper team has a plan to make the most of the opportunity they have: If you can’t get to the ocean, let the ocean come to you.

December 2, 2021December 2, 2021 by David Dickinson

Our Guide to the Only Total Solar Eclipse of 2021

During this weekend’s total solar eclipse, the shadow of the Moon graces the Earth one last time for the year.

Saturday’s total solar eclipse literally spans the ends of the Earth.

The final eclipse for 2021 and the only total solar eclipse of the year occurs on Saturday, December 4^th, as the Moon’s shadow sweeps across a remote segment of the Antarctic continent.