Carolyn Collins Petersen, Author at Universe Today

June 30, 2022June 30, 2022 by Carolyn Collins Petersen

Red Supergiant Stars Bubble and Froth so Much That Their Position in the Sky Seems to Dance Around

This artist’s impression shows the red supergiant star. Using ESO’s Very Large Telescope Interferometer, an international team of astronomers have constructed the most detailed image ever of this, or any star other than the Sun. Credit: ESO/M. Kornmesser

Making a 3D map of our galaxy would be easier if some stars behaved long enough to get good distances to them. However, red supergiants are the frisky kids on the block when it comes to pinning down their exact locations. That’s because they appear to dance around, which makes pinpointing their place in space difficult. That wobble is a feature, not a bug of these massive old stars and scientists want to understand why.

So, as with other challenging objects in the galaxy, astronomers have turned to computer models to figure out why. In addition, they are using Gaia mission position measurements to get a handle on why red supergiants appear to dance.

Artist’s impression of the red supergiant star Betelgeuse as it was revealed with ESO’s Very Large Telescope. It shows a boiling surface and material shed by the star as it ages. Credit: ESO/L.Calçada

June 29, 2022June 29, 2022 by Carolyn Collins Petersen

A Dying Star’s Last Act was to Destroy all Its Planets

Artist's rendition of a white dwarf from the surface of an orbiting exoplanet. Astronomers have found two giant planet candidates orbiting two white dwarfs. More proof that giant planets can surve their stars' red giant phases. Image Credit: Madden/Cornell University

When white dwarfs go wild, their planets suffer through the resulting chaos. The evidence shows up later in and around the dying star’s atmosphere after it gobbles up planetary and cometary debris. That’s the conclusion a team of UCLA astronomers came to after studying the nearby white dwarf G238-44 in great detail. They found a case of cosmic cannibalism at this dying star, which lies about 86 light-years from Earth.

If that star were in the place of our Sun, it would ingest the remains of planets, asteroids, and comets out to the Kuiper Belt. That expansive buffet makes this stellar cannibalism act one of the most widespread ever seen.

June 28, 2022June 28, 2022 by Carolyn Collins Petersen

Curiosity Finds Life-Crucial Carbon in Mars Rocks

Curiosity at Mt. Sharp, Gale Crater, Mars. To the left of the rover are two drill holes into the rocks "Aberlady" and "Kilmarie." Curiosity found high concentrations of clay in both rocks. Image Credit: NASA/JPL-Caltech/MSSS

We are carbon-based life forms. That means the basis for the chemical compounds that forms our life is the element carbon. It’s crucial because it bonds with other elements such as hydrogen and oxygen to create the complex molecules that are part of life. So, when we look for evidence of life elsewhere in the solar system, we look for carbon. That includes Mars.

June 16, 2022June 16, 2022 by Carolyn Collins Petersen

See a Stunning New Picture of the Tarantula Nebula

A mosaic view of 30 Doradus, assembled from Hubble Space Telescope photos, Credit: NASA, ESA, ESO,

When it comes to exciting places to look in the sky, the Tarantula Nebula is hard to beat. It’s got cloudy star-forming regions, hot young stars, and star clusters. It’s one of the brightest and most active star birth areas in the Milky Way’s neighborhood. It’s also got an amazing collection of massive stars. That range of stellar activity makes the Tarantula almost the perfect laboratory to study the mechanics of star formation.

It’s also worth noting that in a fairly short few tens of millions of years, it’ll be a great place to watch supernovae popping off. So, what better way to celebrate this Southern Hemisphere sky treat than a new image of the Tarantula (also known as 30 Doradus)? The one below contains recent ground-based data from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. It’s worthy of a closeup look, so feast your eyes!

This composite image shows the star-forming region 30 Doradus, also known as the Tarantula Nebula. The background image, taken in the infrared, is itself a composite: it was captured by the HAWK-I instrument on ESO’s Very Large Telescope (VLT) and the Visible and Infrared Survey Telescope for Astronomy (VISTA), shows bright stars and light, pinkish clouds of hot gas. The bright red-yellow streaks that have been superimposed on the image come from radio observations taken by the Atacama Large Millimeter/submillimeter Array (ALMA), revealing regions of cold, dense gas which have the potential to collapse and form stars. The unique web-like structure of the gas clouds led astronomers to the nebula’s spidery nickname.

June 16, 2022June 16, 2022 by Carolyn Collins Petersen

Andromeda Tore Apart and Consumed a Neighbor Galaxy

Image of the Andromeda Galaxy, showing Messier 32 to the lower left, which is currently merging with Andromeda. Credit: Wikipedia Commons/Torben Hansen

Things may seem quiet and peaceful in the Andromeda Galaxy when you gaze at it in the sky. However, if you know what to look for, there’s evidence of a violent rumble in this galaxy’s past. That’s the takeaway from research by Ivanna Escala, an astronomer at Carnegie Institution for Science in Pasadena. She found telltale clues for a merger a few billion years ago. That’s when Andromeda actively cannibalized another galaxy.

June 10, 2022June 10, 2022 by Carolyn Collins Petersen

A New Technique Finds a Bundle of Brown Dwarfs

brown dwarf artist's concept — An artist's conception of a T-dwarf brown dwarf object. Credit: Robert Hurt.

Astronomers have a brown dwarf problem. They should be seeing a lot more of these objects, which are cooler than stars but hotter than planets. Yet, there have only been about 40 directly imaged over the past few decades. Why aren’t astronomers finding more of them? It helps to remember that brown dwarfs are dim, low-temperature objects. They don’t stand out in a crowded starfield. If they’re too close to their stars, the starlight hides them from our view. They’re much better observed in the infrared part of the electromagnetic spectrum. All these characteristics make hunting for them difficult.

June 8, 2022June 8, 2022 by Carolyn Collins Petersen

Cosmic Dawn Ended 1.1 Billion Years After the Big Bang

An artist's representation of what the first stars to light up the universe might have looked like in the Cosmic Dawn -- when early stars and galaxies were coming together. Image Credit: NASA/WMAP Science Team

We’re all familiar with the famous opening of the TV show “The Big Bang Theory”. It’s a song that begins with the verse: “The whole Universe was in a hot dense state…” performed by the BareNakedLadies band. Turns out it’s not just a cute line. The Ladies are right—it describes exactly what was going on with the Universe a long time ago. After the Big Bang, the cosmos was an intensely hot, dense, rapidly expanding soup of plasma. It was also in a cosmic “dark age” because there were no sources of light. It was just… well… dark. And hot.

June 7, 2022June 7, 2022 by Carolyn Collins Petersen

Ingenuity has Lost its Sense of Direction, but It’ll Keep on Flying

This image of NASA’s Ingenuity Mars Helicopter was taken by the Mastcam-Z instrument of the Perseverance rover on June 15, 2021, the 114th Martian day, or sol, of the mission. The location, "Airfield D" (the fourth airfield), is just east of the "Séítah" geologic unit. Credits: NASA/JPL-Caltech/ASU/MSSS.

Things are getting challenging for the Ingenuity helicopter on Mars. The latest news from Håvard Grip, its chief pilot, is that the “Little Chopper that Could” has lost its sense of direction thanks to a failed instrument. Never mind that it was designed to make only a few flights, mostly in Mars spring. Or that it’s having a hard time staying warm now that winter is coming. Now, one of its navigation sensors, called an inclinometer, has stopped working. It’s not the end of the world, though. “A nonworking navigation sensor sounds like a big deal – and it is – but it’s not necessarily an end to our flying at Mars,” Grip wrote on the Mars Helicopter blog on June 6. It turns out that the controllers have options.

June 3, 2022June 3, 2022 by Carolyn Collins Petersen

Astronomers Find 116,000 New Variable Stars

This Hubble image shows RS Puppis, a type of variable star known as a Cepheid variable. Credit: Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration Acknowledgment: H. Bond (STScI and Penn State University)

What do two guys from Ohio, the GAIA mission, a worldwide network of ground-based telescopes, machine learning, and citizen scientists all have to do with each other? Thanks to this interesting combo of people and computers, astronomers now have more than 116,000 new variable stars to study. Until now, they knew of about 46,000 of these stars in the Milky Way Galaxy. They had observed maybe 10,000 or so in other galaxies. The discovery gives astronomers even more chances to study variables and understand why they behave the way they do.

May 31, 2022May 31, 2022 by Carolyn Collins Petersen

Why are Uranus and Neptune Different Colors? Haze

NASA’s Voyager 2 spacecraft captured these views of Uranus (on the left) and Neptune (on the right) during its flybys of the planets in the 1980s.

Way back in the late 1980s, the Voyager 2 spacecraft visited Uranus and Neptune. During the flybys, we got to see the first close-up views of those ice giants. Even then, planetary scientists noticed a marked color difference between the two. Yes, they both sport shades of blue. But, if you look closely at Uranus, you see a featureless pale blue planet. Neptune, on the other hand, boasts interesting clouds, dark banding, and dark spots that come and go. They’re all set against a darker blue backdrop.

So, why the difference? Planetary scientists have long suspected aerosols (droplets of gas that have liquids or dust suspended in them) in each atmosphere. But, according to a team of scientists studying the layers of the planets, the hazes those aerosols create may only be part of the story.