Astronomy Archives

May 13, 2023May 13, 2023 by Scott Alan Johnston

Perseverance Finds an Ancient, Fast Flowing River

In a first for Martian water science, NASA’s Perseverance rover has discovered geological evidence of a large, fast-moving river in Mars’ ancient past. The high-energy river once emptied into Jezero crater, which the rover has been exploring since early 2021, and is a totally different water system than anything seen previously on the red planet.

May 12, 2023May 12, 2023 by Evan Gough

JWST Looks at the Atmosphere of a Stormy, Steamy Mini-Neptune

This artist’s concept depicts the planet GJ 1214 b, a “mini-Neptune” with what is likely a steamy, hazy atmosphere. A new study based on observations by NASA’s Webb telescope provides insight into this type of planet, the most common in the galaxy. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)

Just because there’s no Mini-Neptune in our Solar System doesn’t mean they’re not common. They appear to be widespread throughout the Milky Way, and according to NASA, are the most common exoplanet type. GJ 1214 b is one of them.

May 12, 2023May 12, 2023 by Matt Williams

New Images Reveal the Magnetic Fields in the Horsehead Nebula

Magnetic field detections overlaid on a two-color composite of Hubble Space Telescope image taken at two near-IR wavelengths (Mikulski Archive for Space Telescopes). Black and orange segments show magnetic field orientations inferred from JCMT and Palomar Observatory. Credit: Hwang et al. 2023.

Located near the summit of Maunakea, Hawaii, the 15-meter (~49 ft) James Clerk Maxwell Telescope (JCMT) at the East Asia Observatory (EAO) is the largest telescope in the world designed to operate exclusively in the submillimetre-wavelength. In 2018, Molokai’i High School alumna Mallory Go was awarded time with the JCMT under the Maunakea Scholars program. With the assistance of EAO astronomer Dr. Harriet Parsons, Go obtained unique images of the Horsehead Nebula in polarized light, which revealed the nebula’s magnetic fields.

May 12, 2023May 12, 2023 by Evan Gough

It Took Five Years and A Million Images to Make this Atlas of Stellar Nurseries

This image shows the HH 909 A object in the Chamaeleon constellation. New stars are born in the colourful clouds of gas and dust seen here. The infrared observations underlying this image reveal new details in the star-forming regions that are usually obscured by the clouds of dust. Image Credit: ESO/Meingast et al.

Star formation is an intricate process governed by a swarm of variables, and it all happens behind a thick veil of dust. Astrophysicists understand it to a certain degree. But this is nature, and nature doesn’t give up its intimate secrets without a concentrated effort.

To learn more about the star formation process, astronomers imaged five star-forming regions in the southern hemisphere with the ESO’s VISTA telescope. It took five years and over one million images, and the result is the VISIONS survey.

May 12, 2023May 12, 2023 by Paul M. Sutter

Dark Matter Can Make Dark Atoms

Artist's impression of a cloud of trapped antihydrogen atoms. Credit: CERN/Chukman So

A team of theoretical astrophysicists have studied in detail a hypothetical form of dark matter that combines to form dark atoms. They found that the existence of dark atoms can drastically affect the evolution of galaxies.

May 9, 2023May 9, 2023 by Evan Gough

One in Ten Stars Ate a Jupiter (Or Bigger)

This illustration shows a Jupiter-mass exoplanet getting perilously close to its star. Eventually, the star will engulf the planet, something that happens in many stars' lives as they leave the main sequence. Image Credit: C. Carreau / ESA.

In space, cataclysmic events happen to stars all the time. Some explode as supernovae, some get torn apart by black holes, and some suffer other fates. But when it comes to planets, stars turn the tables. Then it’s the stars who get to inflict destruction.

Expanding red giant stars consume and destroy planets that get too close, and a new study takes a deeper look at the process of stellar engulfment.

May 8, 2023May 8, 2023 by Matt Williams

What Does the Milky Way Look Like?

Artist's impression of the Milky Way Galaxy. Credit: ESO

Beginning in 1610, when famed Renaissance polymath Galileo Galilei observed the night sky using a telescope of his own manufacture, astronomers gradually realized that our Solar System is part of a vast collection of stars known today as the Milky Way Galaxy. By the 20th century, astronomers had a good idea of its size and structure, which consisted of a central “bulge” surrounded by an extended disk with spiral arms. Despite all we’ve learned, determining the true morphology of the Milky Way has remained a challenge for astronomers.

Since we, the observers, are embedded in the Milky Way’s disk, we cannot see through the center and observe what’s on the other side. Using various methods, though, astronomers are getting closer to recreating what a “birds-eye” view of the galaxy would look like. For instance, a team of researchers from the Chinese Academy of Sciences (CAS) used the precise locations of very young objects in our galaxy (for the first time) to measure the morphology of the Milky Way. This revealed a multiple-arm morphology consisting of two symmetrical arms in the inner region and many irregular ones in the outer region.

May 8, 2023May 8, 2023 by Evan Gough

Astronomers Watch a Star Gulp Down One of its Planets

A distant Sun-like star will leave the main sequence behind, ending its life of fusion. Then it'll expand into a red giant, totally destroying its four planets. Image Credit: fsgregs Creative Commons Attribution-Share Alike 3.0 Unported

A star like our Sun only shines the way it does because of its intrinsic balance. Stars are massive, and the inward gravitational pressure from all that mass acts to contain the outward thermal pressure from all the fusion inside the star. They are in equilibrium, or on the main sequence if you like, and the result is a spherical mass of plasma that holds its shape and emits radiation with relative stability for billions of years. Like our Sun.

But eventually, stars teeter over the edge and lose their balance. Stars like our Sun will expand, take on a malevolent red hue, and begin to destroy anything that comes within their grasp.

Like a planet.

May 3, 2023May 3, 2023 by Carolyn Collins Petersen

Astronomers are Starting to Find the Wreckage Left Over from the First Stars in the Universe

Using ESO’s Very Large Telescope (VLT), researchers have found for the first time the fingerprints left by the explosion of the first stars in the Universe. They detected three distant gas clouds whose chemical composition matches what we expect from the first stellar explosions. These findings bring us one step closer to understanding the nature of the first stars that formed after the Big Bang. — This artist’s impression shows a distant gas cloud that contains different chemical elements, illustrated here with schematic representations of various atoms. Using ESO’s Very Large Telescope, astronomers have detected three distant gas clouds whose chemical composition matches what we expect from the explosions of the first stars that appeared in the Universe. These early stars can be studied indirectly by analysing the chemical elements they dispersed into the surrounding environment after they died in supernova explosions. The three distant gas clouds detected in this study are rich in carbon, oxygen, and magnesium, but poor in iron. This is exactly the signature expected from the explosions of the first stars.

The first stars were odd ducks. Nobody’s observed them yet (although astronomers are hopeful JWST might spot them someday) but their ghosts remain. Born more than 13.5 billion years ago, they were very different from most of those we know today. These were massive monsters made mostly of hydrogen and helium. And, when they exploded as supernovae, their “starstuff” got scattered to space. Astronomers have now found the chemical remains of those stars in three distant gas clouds observed by European Southern Observatory’s Very Large Telescope.

May 3, 2023May 5, 2023 by Matt Williams

Gravitational Lensing is Helping to Nail Down Dark Matter

Using the gravitational lensing technique, a team was able to examine how light from distant quasar was affected by intervening small clumps of dark matter. Credit: NASA/ESA/D. Player (STScI)

According to the most widely-accepted cosmological model, the majority of the mass in our Universe (roughly 85%) consists of “Dark Matter.” This elusive, invisible mass is theorized to interact with “normal” (or “visible”) matter through gravity alone and not electromagnetic fields, neither absorbing nor emitting light (hence the name “dark”). The search for this matter is ongoing, with candidate particles including Weakly-Interacting Massive Particles (WIMPs) or ultralight bosons (axions), which are at opposite extremes of the mass scale and behave very differently (in theory).

This matter’s existence is essential for our predominant theories of gravity (General Relativity) and particle physics (The Standard Model) to make sense. Otherwise, we may need to radically rethink our theories on how gravity behaves on the largest of scales (aka. Modified Gravity). However, according to new research led by the University of Hong Kong (HKU), the study of “Einstein Rings” could bring us a step closer to understanding Dark Matter. According to their paper, the way Dark Matter alters the curvature of spacetime leaves signatures that suggest it could be made up of axions!