Astronomy Archives

November 7, 2022November 6, 2022 by Scott Alan Johnston

Planets Make it Harder to Figure out a Star’s age

Active star, nearby exoplanet, and inactive companion star for NASA's Chandra X-ray Observatory. 2022

Estimating stellar age has always been a challenge for astronomers. Now, a certain class of exoplanets is making the process even more complicated. Hot Jupiters – gas giants with orbital periods smaller than that of Mercury – appear to have an anti-aging effect on their stars, according to a new study. These enormous planets inflict both magnetic and tidal interference on their host star, speeding up the star’s rotation and causing them to emit X-rays more energetically, both of which are hallmarks of stellar youth. The result calls into question some of what we previously believed about stellar age, and offers a glimpse at the ongoing interconnectivity between a star and its planets long after their formation.

November 6, 2022November 2, 2022 by Paul M. Sutter

When Black Holes Collide They Also Produce Neutrinos

Still image from a numerical simulation of an unequal mass binary black hole merger, with parameters consistent with GW190412. [Image credit: N. Fischer, H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), Simulating eXtreme Spacetimes project]

Ever since astronomers first detected ultra high energy neutrinos coming from random directions in space, they have not been able to figure out what generates them. But a new hypothesis suggests an unlikely source: the mergers of black holes.

November 5, 2022November 5, 2022 by Anton Pozdnyakov

Worrying Solar Storm Data, Falcon Heavy is Back, Total Lunar Eclipse

Historical data about solar storms carved in trees, and it’s a bit worrying. Falcon Heavy’s back after 40 months of absence. There’s a meteor shower and a total lunar eclipse in the coming days. And JWST gave us yet another version of Pillars of Creation.

November 5, 2022November 2, 2022 by Paul M. Sutter

It’s Tough to Find Evidence of Stars Eating Planets

Tragically sometimes stars engulf their own planets. While most stars are able to quickly cover up the evidence for their crime, a new study by astronomers has revealed that in some cases the evidence can linger for up to two billion years.

November 4, 2022November 4, 2022 by Matt Williams

What Happens to Hot Jupiters when their Star Becomes a Red Giant?

exoplanet hot jupiter transiting its star — This artist’s impression shows an ultra-hot exoplanet as it is about to transit in front of its host star. Credit: ESO

The study of extrasolar planets has led to some astounding discoveries, many of which have defied the expectations of astronomers and challenged our notions about the forms planetary systems can take. For example, the discovery of Jupiter-sized planets that orbit closely to their stars (“Hot Jupiters”) defied what astronomers suspected about gas giants. Previously, the general consensus was that gas giants form beyond the “Frost Line” – the boundary beyond which volatile elements (like water) freeze solid – and remain there for the rest of their lives.

Interestingly, this will happen when our Sun leaves its main sequence phase and enters its Red Giant Branch (RGB) phase. This raises the question of what happens to Hot Jupiters when their parent stars expand to become Red Giants. Using advanced 3D simulations, a team of researchers led by the Compact Object Mergers: Population Astrophysics and Statistics (COMPAS) consortium simulated how red giants will expand to engulf Hot Jupiters. Their findings could answer another mystery confronting astronomers, which is why some binary systems have one rapidly-rotating star with strange chemical compositions.

November 4, 2022November 2, 2022 by Paul M. Sutter

Solar Orbiter Records a Stunning Timelapse of Solar Activity as it Completes its Latest Flyby

The darker area on this image of the Sun's surface is the southern extension of the northern hemisphere polar corona. The coronal hole is a source of fast-moving streams of particles from the Sun, which can cause auroras here on Earth. Image: NASA/SDO

The sun is currently sleeping. Its surface and corona are relatively quiet as it prepares to ramp up for an expected phase of high activity in 2025. This past October, the ESA’s Solar Orbiter was able to sneak in a close-up peak at the Sun as it slumbers.

November 4, 2022November 4, 2022 by David Dickinson

Our Guide to Tuesday’s Total Lunar Eclipse

The November 8th total lunar eclipse spans the Pacific and is the last until 2025.

Set your alarms: if skies cooperate, next Tuesday morning’s lunar eclipse on November 8^th is worth getting up for and braving the cold. Not only is this one of the top astronomical events for 2022, but it’s also the last total lunar eclipse for a while…until, in fact, March 14, 2025.

November 3, 2022November 3, 2022 by Andy Tomaswick

How do you Keep a Solar Sail Stable?

Solar sailing seems like a simple concept – instead of being pushed along by the wind, as in a typical sailing ship, a spacecraft can use highly reflective said to be pushed along simply by sunlight. But as with almost all engineering challenges, that technique is much easier said than done. Sunlight can head up one side of a sail more than another, causing the ship to rotate unexpectedly. Other unforeseen situations could arise that can also have catastrophic consequences for any mission using this propulsion technology. Luckily, there is a way to account for those situations, though it involves a lot of math. Control theory is common in system design, and now researchers at Beihang University have devised a control scheme that they think could help minimize the risk to solar sails.

November 3, 2022November 2, 2022 by Paul M. Sutter

You Can Help Measure Light Pollution with Your Phone

Urban sprawl and accompanying light pollution is an issue for both astronomers and fireflies. This view shows the light dome from the city of Duluth, Minn. 20 miles north of town. It erases the dark skies. Credit: Bob King

There’s no question that light pollution is a growing problem. Thankfully many scientists and advocates are working for change. And you can be a part of that change with a simple app that you can download to catalog the street lights in your neighborhood.

November 3, 2022November 3, 2022 by Anton Pozdnyakov

25 More Years for Webb, LUVOIR and Quantum Telescopes

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

What’s the current state of James Webb? What were the main technical difficulties and what does the future look like? What comes after JWST and LUVOIR? Will it be possible to ever build quantum telescopes? We’ve got the answers.!