Evan Gough, Author at Universe Today

November 20, 2024November 20, 2024 by Evan Gough

Main Sequence and White Dwarf Binaries are Hiding in Plain Sight

This ALMA image shows the binary HD101584. The pair of stars share a common envelope, and are surrounded by complex clouds of gas. Image Credit: By ALMA, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=86644758

Some binary stars are unusual. They contain a main sequence star like our Sun, while the other is a “dead” white dwarf star that left fusion behind and emanates only residual heat. When the main sequence star ages into a red giant, the two stars share a common envelope.

This common envelope phase is a big mystery in astrophysics, and to understand what’s happening, astronomers are building a catalogue of main sequence-white dwarf binaries.

November 20, 2024November 20, 2024 by Evan Gough

What a Misplaced Meteorite Told Us About Mars

The Lafayette Meteorite was chipped off the surface of Mars and then sped through space for roughly 11 million years. It eventually found its way into a drawer at Purdue University in 1931 and has since been teaching scientists about Mars. (Photo provided by Purdue Brand Studio.)

11 million years ago, Mars was a frigid, dry, dead world, just like it is now. Something slammed into the unfortunate planet, sending debris into space. A piece of that debris made it to Earth, found its way into a drawer at Purdue University, and then was subsequently forgotten about.

Until 1931, when scientists studied and realized it came directly from Mars. What has it told them about the red planet?

November 20, 2024November 20, 2024 by Evan Gough

Uranus is Getting Colder and Now We Know Why

This zoomed-in image of Uranus, captured by Webb’s Near-Infrared Camera (NIRCam) Feb. 6, 2023, reveals stunning views of the planet’s rings. The planet's upper atmosphere has been cooling for decades, New research has an explanation. Credit: NASA, ESA, CSA, STScI IMAGE PROCESSING: Joseph DePasquale (STScI).

Uranus is an oddball among the Solar System’s planets. While most planets’ axis of rotation is perpendicular to their orbital plane, Uranus has an extreme tilt angle of 98 degrees. It’s flopped over on its side, likely from an ancient collision. It also has a retrograde orbit, opposite of the other planets.

The ice giant also has an unusual relationship with the Sun that sets it apart from other planets.

November 19, 2024November 19, 2024 by Evan Gough

The Strange Pulsar at the Center of the Crab Nebula

Hubble image of the Crab Nebula supernova remnant captured with the Wide Field and Planetary Camera 2. Credit: NASA, ESA, J. Hester and A. Loll (ASU)

Thanks to the Hubble Space Telescope, we all have a vivid image of the Crab Nebula emblazoned in our mind’s eyes. It’s the remnant of a supernova explosion Chinese astronomers recorded in 1056. However, the Crab Nebula is more than just a nebula; it’s also a pulsar.

The Crab Pulsar pulsates in an unusual ‘zebra’ pattern, and an astrophysicist at the University of Kansas thinks he’s figured out why.

November 18, 2024November 18, 2024 by Evan Gough

Up to a Third of Stars Ate Some of their Planets

Ultra-short period planets can be engulfed by their stars. They may be responsible for differences in metallicity between sibling stars. Image Credit: NASA, ESA and A. Schaller

In recent years, astronomers have developed techniques to measure the metal content of stars with extreme accuracy. With that capability, astronomers have examined sibling stars to see how their metallicity differs. Some of these co-natal stars have pronounced differences in their metallicity.

New research shows that stars engulfing rocky planets are responsible.

November 15, 2024November 15, 2024 by Evan Gough

It Takes Very Special Conditions to Create This Bizarre Stellar Spectacle

A binary star system called R Aquarii undergoes violent eruptions that blast out huge filaments of glowing gas in this Hubble Space Telescope image. Image Credit: NASA, ESA, Matthias Stute , Margarita Karovska , Davide De Martin (ESA/Hubble), Mahdi Zamani (ESA/Hubble)

A stellar odd couple 700 light-years away is creating a chaotically beautiful display of colourful, gaseous filaments. The Hubble captured the pair, named R Aquarii, and their symbiotic interactions. Every 44 years the system’s violent eruptions blast out filaments of gas at over 1.6 million kilometers per hour.

November 14, 2024November 14, 2024 by Evan Gough

A New Way to Detect Daisy Worlds

Daisy Worlds are planets where the biosphere regulates the environment to keep it habitable. Earth is one, sort of. Can we use information theory to identify agnostic biosignatures from these living worlds? Image Credit: NASA

The Daisy World model describes a hypothetical planet that self-regulates, maintaining a delicate balance involving its biogeochemical cycles, climate, and feedback loops that keep it habitable. It’s associated with the Gaia Hypothesis developed by James Lovelock. How can we detect these worlds if they’re out there?

By looking closely at information.

November 13, 2024November 13, 2024 by Evan Gough

Lessons From Ancient Earth’s Atmosphere: From Hostile to Hospitable

Earth's ancient atmosphere was much different than now. How did it transition from hostile to hospitable? If scientists can figure that out, they'll be better able to understand exoplanets and their atmospheres. Image Credit: Tohoku University

Will we ever understand how life got started on Earth? We’ve learned much about Earth’s long, multi-billion-year history, but a detailed understanding of how the planet’s atmospheric chemistry evolved still eludes us. At one time, Earth was atmospherically hostile, and its transition from that state to a planet teeming with life followed a complex path.

November 12, 2024November 12, 2024 by Evan Gough

An Otherworldly Cloud Over New Zealand

Landsat 8’s Operational Land Imager captured this unique lenticular cloud that forms over the Otago region of New Zealand’s South Island. Image Credit: NASA/Lauren Dauphin; USGS

Filmmakers love New Zealand. Its landscapes evoke other worlds, which explains why so much of The Lord of the Rings was filmed there. The country has everything from long, subtropical sandy beaches to active volcanoes.

The country’s otherworldliness extends into its atmosphere, where a cloud nicknamed the “Taieri Pet” forms when conditions are right.

November 12, 2024November 12, 2024 by Evan Gough

A Spider Stellar Engine Could Move Binary Stars Halfway Across a Galaxy

Illustration of a millisecond pulsar consuming material from a companion star. Pulsars that evaporate their companions rather than consuming them could serve as stellar engines. Credit: NASA / GSFC SVS / Dana Berry

Eventually, every stellar civilization will have to migrate to a different star. The habitable zone around all stars changes as they age. If long-lived technological civilizations are even plausible in our Universe, migration will be necessary, eventually.

Could Extraterrestrial Intelligences (ETIs) use stars themselves as stellar engines in their migrations?