Space News & Blog Articles

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.

Meanwhile, another comet has also put on a show, mostly hidden from view: Comet 96P Machholz.

The comet reached perihelion on January 31st at 0.124 Astronomical Units (AU)/18.5 million kilometers from the Sun (three times closer to the Sun than Mercury at its closest). The comet put on a fine performance, sliding through the field of view of the joint NASA/ESA SOHO (the Solar and Heliospheric Observatory) LASCO C3 imager view. Though SOHO’s primary mission is to monitor solar activity, it does pick up sungrazing and even doomed comets from time to time, mainly using its LASCO C2 and C3 imagers, which are equipped with occulting disks to block out the Sun. Since arriving at the sunward Lagrange 1 point in late 1995, SOHO has detected an amazing 4,551 sungrazing comets and counting, most of which were found thanks to the efforts of dedicated online volunteers. And to think, only less than a dozen sungrazing comets were known of, prior to the launch of SOHO. It’ll be sad to see this amazing resource coming to a scheduled end in 2025.

Comet 96P displayed a fine fantail as it swept through the view. But what’s truly amazing is that the comet seems to have retained some of that brightness as it emerges into the dawn sky in early February. astrophotographer Michael Jaeger managed to nab the comet on the morning of February 5th from Martinsberg, Austria. The comet was just 15 degrees west of the Sun at the time, sporting a one degree long tail, about twice the diameter of the Full Moon.

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.

The prospect of finding Earth-like planets raises the prospect of finding life elsewhere. But they’re difficult to spot. Of the approximately 5,200 exoplanets we know of, only a tiny minority can be described as Earth-like. NASA calls them terrestrial planets, and they range from half of Earth’s mass to twice Earth’s mass. But the designation only refers to their size and their composition.

An Earth-sized planet isn’t Earth-like unless its star behaves well. And that’s been a problem for planets orbiting red dwarfs. Red dwarfs are notorious for violent UV flaring. That can strip away the atmosphere of any planet in its habitable zone, Earth-like or not.

A team of astronomers from the Max Planck Institute for Astronomy think they’ve found a planet orbiting a red dwarf that might be an exception to the rule. Even though the planet is tidally locked, researchers think it could remain habitable across its dayside. They also think the planet is a good candidate to search for biosignatures on.

The researchers reported their findings in a paper titled “The CARMENES search for exoplanets around M dwarfs. Wolf 1069 b: Earth-mass planet in the habitable zone of a nearby, very low-mass star.” The paper is published in the journal Astronomy and Astrophysics, and the lead author is Diana Kossakowski. Kossakowski is from the Department of Planet and Star Formation at the MPIA.

The Tarantula Nebula, also called 30 Doradus, is the brightest star-forming region in our part of the galaxy. It’s in the Large Magellanic Cloud (LMC) and contains the most massive and hottest stars we know of. The Tarantula Nebula has been a repeat target for the Hubble since the telescope’s early years.

Star formation is an extremely detailed process, and the Tarantula Nebula’s bright star-forming regions are a natural laboratory for studying the interplay between stars, gas, and dust. This image comes from two Hubble observing programs aimed at 30 Doradus. Scylla studies how interstellar dust interacts with starlight in a variety of environments, and Ulysses studies the stars themselves in 30 Doradus.

30 Doradus is chock full of interesting observing targets. This featured image mostly shows the star cluster NGC 2060. NGC 2060 is a loose star cluster within one of the nebula’s superbubbles, a cavity hundreds of light years across. The cluster is approximately 10 million years old.

For context, the image below is a wide image of the Tarantula Nebula showing where the Hubble image is located.

Astronomers can study multiple aspects of star formation in the region. Multiple observing programs by multiple telescopes over the years have studied how hot, young, massive stars carve out bubbles in the gas. They’ve also studied oddball rapidly rotating stars. They’ve studied the dark lanes of thick dust and Bok globules. There are even supernova remnants in the regions, as well as HII regions. Almost any object of study is present in the region, and there’s even a stellar-mass black hole. The region is scientifically important because it allows multi-epoch surveys, which means astronomers can study stars at all stages of evolution.

Galaxies fill a lot of roles in the universe. The most obvious one is star formation factories. Without that activity, the cosmos would be a very different place. The European Southern Observatory and the Atacama Large Millimeter Array recently zeroed in on the galaxy NGC 4303. Their goal: to take a multi-wavelength view of its star formation activity.

The object was to help astronomers understand how stars form in galactic environments. The resulting image shows a golden glow of molecular clouds of gas threading through the spiral arms and the existence of already-formed stars.

NGC 4303 is a beautiful spiral galaxy located more than 50 million light-years away, in the Virgo Cluster of galaxies. Astronomers rank it as a weakly barred spiral. It also looks like it may have a ring structure within its spiral arms. The arms sparkle with star formation, making it a starburst galaxy. There’s has an active nucleus there, too, likely hiding a supermassive black hole.

A Hubble Space Telescope view of NGC 4303 shows the active core of the galaxy, along with a scattering of its stars and star formation regions. Courtesy: ESA/Hubble/NASA

This galaxy is classified as a late-type spiral. That means it turned gas into stars more slowly in the past and still has a lot left today. Sure enough, based on this and other studies, it appears very rich in neutral hydrogen. That’s the building block of stars.