Astronomy Archives

February 25, 2023February 25, 2023 by Matt Williams

59 New Planets Discovered in Our Neighborhood

An artist’s concept of a high-resolution image of an Earth-size planet in the cool range of the habitable zone of a nearby M dwarf. © José A. Caballero (CAB, CSIC-INTA), Javier Bollaín (Render Area)

The hunt for habitable extrasolar planets continues! Thanks to dedicated missions like Kepler, TESS, and Hubble, the number of confirmed extrasolar planets has exploded in the past fifteen years (with 5,272 confirmed and counting!). At the same time, next-generation telescopes, spectrometers, and advanced imaging techniques are allowing astronomers to study exoplanet atmospheres more closely. In short, the field is shifting from the process of discovery to characterization, allowing astronomers to more tightly constraint habitability.

Finding potentially-habitable “Earth-like” planets around these fainter stars is the purpose of the Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs (CARMENES), located at the Calar Alto Observatory in Spain. In a study that appeared in Astronomy & Astrophysics today, the CARMENES Consortium published data (Data Release 1) data from about 20,000 observations taken between 2016 and 2020. Among the measurements obtained from 362 nearby cool stars, the DR1 contained data on 59 new planets.

February 22, 2023February 23, 2023 by Matt Williams

Clouds of Carbon Dust Seen When the Universe was Less Than a Billion Years Old

This view of nearly 10,000 galaxies is called the Hubble Ultra Deep Field. It shows some galaxies in the early Universe, (which appear as red blobs). Credit: NASA/ESA/HUDF

The Milky Way Galaxy contains an estimated one hundred billion stars. Between these lies the Interstellar Medium (ISM), a region permeated by gas and dust grains. This dust is largely composed of heavier elements, including silicate minerals, ice, carbon, and iron compounds. This dust plays a key role in the evolution of galaxies, facilitating the gravitational collapse of gas clouds to form new stars. This galactic dust is measurable by how it attenuates starlight from distant galaxies, causing it to shift from ultraviolet to far-infrared radiation.

However, the origin of various dust grains is still a mystery, especially during the early Universe when heavier elements are thought to have been scarce. Previously, scientists believed that elements like carbon took hundreds of millions of years to form and could not have existed before about 2.5 billion years after the Big Bang. Using data obtained by the JWST Advanced Deep Extragalactic Survey (JADES), an international team of astronomers and astrophysicists report the detection of carbonaceous grains around a galaxy that existed roughly 1 billion years after the Big Bang.

February 22, 2023February 22, 2023 by David Dickinson

Cosmic Conjunction: Jupiter Meets Venus on March 1st

Jupiter vs Venus — Jupiter meets Venus from 2015. Image credit: Roger Hutchison.

The two brightest planets pass less than half a degree apart at dusk during a spectacular conjunction on the night of March 1^st.

It has begun. Once every 12 to 18 months or so, I start fielding “what are those two bright objects in the sky?” questions. They’re none other than the third and fourth brightest natural objects in the sky (behind the Sun and the Moon), the planets Jupiter and Venus. If skies are clear, you can see them get ever closer together from one night to the next, as they meet up during a spectacular conjunction on the night of March 1st/2nd.

February 20, 2023February 20, 2023 by Matt Williams

All of Jupiter's Large Moons Have Auroras

Artist's concept of aurorae on Ganymede - auroral belt shifting may indicate a subsurface saline ocean. Credit: NASA/ESA

Jupiter is well known for its spectacular aurorae, thanks in no small part to the Juno orbiter and recent images taken by the James Webb Space Telescope (JWST). Like Earth, these dazzling displays result from charged solar particles interacting with Jupiter’s magnetic field and atmosphere. Over the years, astronomers have also detected faint aurorae in the atmospheres of Jupiter’s largest moons (aka. the “Galilean Moons“). These are also the result of interaction, in this case, between Jupiter’s magnetic field and particles emanating from the moons’ atmospheres.

Detecting these faint aurorae has always been a challenge because of sunlight reflected from the moons’ surfaces completely washes out their light signatures. In a series of recent papers, a team led by the University of Boston and Caltech (with support from NASA) observed the Galilean Moons as they passed into Jupiter’s shadow. These observations revealed that Io, Europa, Ganymede, and Callisto all experience oxygen-aurorae in their atmospheres. Moreover, these aurorae are deep red and almost 15 times brighter than the familiar green patterns we see on Earth.

February 19, 2023February 19, 2023 by Anton Pozdnyakov

Meteor Explodes Over English Channel, Moon Breakthrough, Dark Matter Galaxy

Blue Origin wants to build solar panels on the Moon, out of the Moon, SpaceX sold its floating landing pads, and another asteroid hits Earth exactly where and when astronomers predicted.

February 16, 2023February 16, 2023 by Evan Gough

What Would Happen if the Solar System Gained a Super-Earth?

This illustration shows the super-Earth exoplanet 55 Cancri e with its star. What would our Solar System be like if it was home to a super-Earth like this one? Credit: NASA/JPL

In this era of exoplanet discovery, astronomers have found over 5,000 confirmed exoplanets, with thousands more awaiting confirmation and many billions more waiting to be discovered. These exoplanets exist in a bewildering spectrum of sizes, compositions, orbital periods, and just about every other characteristic that can be measured.

Learning about them has also shed light on our Solar System. We used to think of it as an archetypal arrangement of planets since it’s all we had to go on. But now we know we might be the outlier because we have no Super-Earth.

February 16, 2023February 16, 2023 by Matt Williams

Webb Sees Three Galaxy Clusters Coming Together to Form a Megacluster

Pandora's Cluster, imaged by the UNCOVER project using the JWST. Credit: Credits: NASA/ESA/CSA, I. Labbe/R. Bezanson/ Alyssa Pagan (STScI)

As the successor to the venerable Hubble Space Telescope, one of the main duties of the James Webb Space Telescope has been to take deep-field images of iconic cosmic objects and structures. The JWST’s next-generation instruments and improved resolution provide breathtakingly detailed images, allowing astronomers to learn more about the cosmos and the laws that govern it. The latest JWST deep-field is of a region of space known as Abell 7244 – aka. Pandora’s Cluster – where three galaxy clusters are in the process of coming together to form a megacluster.

February 15, 2023February 15, 2023 by Evan Gough

A Galaxy has Been Found that’s Almost Entirely Dark Matter

This is the galaxy Dragonfly 44, which is an Ultra Diffuse Galaxy (UDG.) It's about as massive as the Milky Way, but only 1% as luminous. Astronomers think it's almost entirely made of dark matter. Now scientists have found another one like it. Image Credit: By Teymursaif - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=95121595

Astronomers have discovered a galaxy with very little or no stellar mass. Galaxies like these are called ‘dark galaxies.’ It contains clouds of gas but very few stars, possibly none. This is the only isolated dark dwarf galaxy in the local universe.

February 14, 2023February 14, 2023 by Evan Gough

Astronomers Spot a Rogue Supermassive Black Hole, Hurtling Through Space Leaving Star Formation in its Wake

This artist's conception illustrates a supermassive black hole (central black dot) at the core of a young, star-rich galaxy. Now astronomers have found a rogue SMBH travelling through space. Image credit: NASA/JPL-Caltech

Supermassive black holes (SMBHs) lurk in the center of large galaxies like ours. From their commanding position in the galaxy’s heart, they feed on gas, dust, stars, and anything else that strays too close, growing more massive as time passes. But in rare circumstances, an SMBH can be forced out of its position and hurtle through space as a rogue SMBH.

February 13, 2023February 16, 2023 by Matt Williams

Are We Entering the Era of Quantum Telescopes?

Beyond James Webb and LUVOIR, the future of astronomy could come down to telescopes that rely on quantum mechanics. Credit: Anton Pozdnyakov

For astronomers, one of the greatest challenges is capturing images of objects and phenomena that are difficult to see using optical (or visible light) telescopes. This problem has been largely addressed by interferometry, a technique where multiple telescopes gather signals, which is then combined to create a more complete picture. Examples include the Event Horizon Telescope, which relies on observatories from around the world to capture the first images of the supermassive black hole (SMBH) at the center of the M87 galaxy, and of Sagittarius A* at the center of the Milky Way.

That being said, classic interferometry requires that optical links be maintained between observatories, which imposes limitations and can lead to drastically increased costs. In a recent study, a team of astrophysicists and theoretical physicists proposed how these limitations could be overcome by relying on quantum mechanics. Rather than relying on optical links, they propose how the principle of quantum entanglements could be used to share photons between observatories. This technique is part of a growing field of research that could lead to “quantum telescopes” someday.