Check Out This Great View of Comet 96P Machholz, Courtesy of SOHO

Comet 96P
Comet 96P Machholz, as seen from SOHO's LASCO C3 imager. Credit: NASA

Now’s the time to catch periodic Comet 96P Machholz on its encore dawn performance, before it slides out of view.

So, have you been following the touted ‘green comet,’ E3 ZTF? To be sure, it’s nothing more than a fuzzy patch, a binocular comet sliding through the constellation Auriga looking like a globular cluster that refuses to resolve into focus. Though E3 ZTF may not live up to the hype, it does have one thing going for it: it is currently well-placed for northern hemisphere viewers. It also put on a great show for astrophotographers as it recently completed an orbital plane-crossing, as seen from our Earthly vantage point.

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Earth-Sized Planet Found At One of the Lightest Red Dwarfs

Artist’s conception of a rocky Earth-mass exoplanet like Wolf 1069 b orbiting a red dwarf star. If the planet has retained its atmosphere, chances are high that it would feature liquid water and habitable conditions over a wide area of its dayside. Image Credit: NASA/Ames Research Center/Daniel Rutter

Astronomers have found another Earth-sized planet. It’s about 31 light-years away and orbits in the habitable zone of a red dwarf star. It’s probably tidally locked, which can be a problem around red dwarf stars. But the team that found it is optimistic about its potential habitability.

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A.I. Finds a New Way to Build Multiple-Star Systems

A false-color image of NGC 6334 from multiple telescopes. The area is believed to be a hotspot of furious star birth. Credit: S. Willis (CfA+ISU); ESA/Herschel; NASA/JPL-Caltech/ Spitzer; CTIO/NOAO/AURA/NSF

Over over 50% of high mass stars reside in multiple star systems. But due to their complex orbital interactions, physicists have a difficult time understanding just how stable and long-lived these systems are. Recently a team of astronomers applied machine learning techniques to simulations of multiple star systems and found a new way that stars in such systems can arrange themselves.

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Astronomers use Earthquakes to Understand Glitches on Neutron Stars

Simulation of a possible quadrupole magnetic field configuration for a pulsar with hot spots in only the southern hemisphere. Credits: NASA's Goddard Space Flight Center

A team of astronomers have used a model of earthquakes to understand glitches in the timing of pulsars. Their results suggest that pulsars may have interiors that are far stranger than can be imagined.

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The James Webb May See the First Stars to Appear in the Universe

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
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

Astronomers continue to hunt for the elusive kind of star known as Population III stars, the first stars to appear in the young universe. New research has revealed that the James Webb Space Telescope may be on the cusp of discovering them.

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This Binary System is Destined to Become a Kilonova

This is an artist’s impression of the first confirmed detection of a star system that will one day form a kilonova — the ultra-powerful, gold-producing explosion created by merging neutron stars. Image Credit: CTIO/NOIRLab/NSF/AURA/J. da Silva/Spaceengine/M. Zamani

Kilonovae are extraordinarily rare. Astronomers think there are only about 10 of them in the Milky Way. But they’re extraordinarily powerful and produce heavy elements like uranium, thorium, and gold.

Usually, astronomers spot them after they’ve merged and emitted powerful gamma-ray bursts (GRBs.) But astronomers using the SMARTS telescope say they’ve spotted a kilonova progenitor for the first time.

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How Can We Know if We’re Looking at Habitable exo-Earths or Hellish exo-Venuses?

How can astronomers tell exo-Earths and exo-Venuses apart? Polarimetry might be the key. Image Credits: NASA

The differences between Earth and Venus are obvious to us. One is radiant with life and adorned with glittering seas, and the other is a scorching, glowering hellhole, its volcanic surface shrouded by thick clouds and visible only with radar. But the difference wasn’t always clear. In fact, we used to call Venus Earth’s sister planet.

Can astronomers tell exo-Earths and exo-Venuses apart from a great distance?

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The Historic Discussion of Ptolemy’s Star Catalog

A page from the star catalog in a 1515 printing of Ptolemy's Almagest.
A page from the star catalog in a 1515 printing of Ptolemy's Almagest.

From the time of its writing in the 2nd century CE, Claudius Ptolemy’s Almagest stood at the forefront of mathematical astronomy for nearly 1,500 years. This work included a catalog of 1,025 stars, listing their coordinates (in ecliptic longitude and latitude) and brightnesses. While astronomers within a few centuries realized that the models for the sun, moon, and planets all had issues (which we today recognize as being a result of them being incorrect, geocentric models relying on circles and epicycles instead of a heliocentric model with elliptical orbits), the catalog of stars was generally believed to be correct.

That was, until the end of the 16th century, when the renowned observational astronomer Tycho Brahe realized that there was a fundamental flaw with the catalog: the ecliptic longitudes were low by an average of 1 degree.

What’s more, Brahe proposed an explanation for why. He suggested that Ptolemy had stolen the data from the astronomer Hipparchus some 250 years earlier, and then incorrectly updated the coordinates.

The question of whether this was a cosmic coincidence or the oldest case of scientific plagiarism is a question that historians of astronomy have argued for over 400 years.

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The First Stars May Have Weighed More Than 100,000 Suns

The epoch of reionization was when light from the first stars could travel through the early Universe. At this time, galaxies began assembling, as did black holes. Why did some early galaxies have ancient stars? That's a question JWST will help answer. Credit: Paul Geil & Simon Mutch/The University of Melbourne
The epoch of reionization was when light from the first stars could travel through the early Universe. At this time, galaxies began assembling, as did black holes. Why did some early galaxies have ancient stars? That's a question JWST will help answer. Credit: Paul Geil & Simon Mutch/The University of Melbourne

The universe was simply different when it was younger. Recently astronomers have discovered that complex physics in the young cosmos may have led to the development of supermassive stars, each one weighing up to 100,000 times the mass of the Sun.

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