Plants Would Still Grow Well Under Alien Skies

This is an artist's illustration of the rocky super Earth HD 219134. It orbits a K-type star, a long-lived stable type of main sequence star. The light from K-type stars is different than the Sun's. Can Earth plants photosynthesize effectively near these stars? Image Credit: By NASA/JPL-Caltech - http://photojournal.jpl.nasa.gov/jpeg/PIA19833.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=41995148

Photosynthesis changed Earth in powerful ways. When photosynthetic organisms appeared, it led to the Great Oxygenation Event. That allowed multicellular life to evolve and resulted in the ozone layer. Life could venture onto land, protected from the Sun’s intense ultraviolet radiation.

But Earth’s photosynthetic organisms evolved under the Sun’s specific illumination. How would plants do under other stars?

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A Star Was Kicked Out of a Globular Cluster by an Intermediate-Mass Black Hole

The M15 Globular Cluster (aka. Great Hercules Cluster). Astronomers suspect the existence of one or more intermediate-mass black holes at its heart. Credit: NASA/ESA/HST
The M15 Globular Cluster (aka. Great Hercules Cluster). Astronomers suspect the existence of one or more intermediate-mass black holes at its heart. Credit: NASA/ESA/HST

Astronomers have solid evidence for the existence of stellar-mass black holes and supermassive black holes. However, evidence for Intermediate Black Holes (IMBHs) is more elusive. Their existence remains hypothetical.

However, study by study, evidence is accumulating for IMBHs. The latest comes from the globular cluster M15, where a fast-moving star suggests the presence of something massive. Could it be an elusive IMBH?

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High Resolution Images Show Bubbling Gas on the Surface of Another Star

Astronomers have captured a sequence of images of a star other than the Sun in enough detail to track the motion of bubbling gas on its surface. The images of the star, R Doradus, were obtained with the Atacama Large Millimeter/submillimeter Array (ALMA). This panel shows three of these real images, taken with ALMA on 18 July, 27 July and 2 August 2023. The giant bubbles — 75 times the size of the Sun — seen on the star’s surface are the result of convection motions inside the star. The size of the Earth’s orbit is shown for scale. Credit: ALMA (ESO/NAOJ/NRAO)/W. Vlemmings et al.

Although stars are enormous, they’re extremely far away, and appear as point sources in telescopes. Usually, you never get to see more than a pixel. Now astronomers have used the Atacama Large Millimeter/submillimeter Array (ALMA) to resolve details on the surface of the star R Doradus and track its activity for 30 days. The images revealed giant, hot bubbles of gas 75 times larger than the entire Sun. R Doradus is 350 times larger than our Sun, but only 180 light-years away.

“This is the first time the bubbling surface of a real star can be shown in such a way,“ said Wouter Vlemmings, a professor at Chalmers University of Technology in Sweden, and lead author of the study, in a press release from the European Southern Observatory (ESO). “We had never expected the data to be of such high quality that we could see so many details of the convection on the stellar surface.”

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Polaris, Earth’s North Star, Has A Surprisingly Spotted Surface

An artist's conception shows Polaris A with a close companion, known as Polaris Ab. Yet another companion star, Polaris B, can be seen as a speck in the background at right. Credit: STScI

Humanity’s been fortunate to have a star situated over Earth’s north pole. The star, known as Polaris, or the North Star, has guided many sailors safely to port. But Polaris is a fascinating star in its own right, not just because of its serendipitous position.

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Stars Can Survive Their Partner Detonating as a Supernova

A binary star system consisting of two stars: a dense neutron star (lower right) and a normal Sun-like star (upper left). The neutron star formed in a supernova explosion and the Sun-like star survived it. Credit: Caltech/R. Hurt (IPAC)
A binary star system consisting of two stars: a dense neutron star (lower right) and a normal Sun-like star (upper left). The neutron star formed in a supernova explosion and the Sun-like star survived it. Credit: Caltech/R. Hurt (IPAC)

When a massive star dies in a supernova explosion, it’s not great news for any planets or stars that happen to be nearby. Generally, the catastrophic event crisps nearby worlds and sends companion stars careening through space. So, astronomers were pretty surprised to find 21 neutron stars—the crushed stellar cores left over after supernova explosions—orbiting in binary systems with Sun-like stars.

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Do We Now Have an Accurate Map of Nearby Stars?

This image shows the bright stars within 15 parsecs of the Sun. If red dwarfs and brown dwarfs were included, there would be far more stars. But those stars are difficult to spot. Have we found all of them yet? Image Credit: By Andrew Z. Colvin - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=14359465

If the Sun has a stellar neighbourhood, it can be usefully defined as a 20 parsec (65 light-years) sphere centred on our star. Astronomers have been actively cataloguing the stellar population in the neighbourhood for decades, but it hasn’t been easy since many stars are small and dim.

Even with all of the challenges inherent in the effort, astronomers have made steady progress. Do we now have a complete catalogue?

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The JWST Peers into the Heart of Star Formation

In this image of the Serpens Nebula from the Near-InfraRed Camera (NIRCam) on the NASA/ESA/CSA James Webb Space Telescope, astronomers found a grouping of aligned protostellar outflows within one small region (the top left corner). In the Webb image, these jets are identified by bright red clumpy streaks, which are shockwaves caused when the jet hits the surrounding gas and dust. Image Credit: NASA, ESA, CSA, STScI, K. Pontoppidan (NASA’s Jet Propulsion Laboratory), J. Green (Space Telescope Science Institute)

The James Webb Space Telescope has unlocked another achievement. This time, the dynamic telescope has peered into the heart of a nearby star-forming region and imaged something astronomers have longed to see: aligned bipolar jets.

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The Nearby Star Clusters Come from Only Three Places

The most well-known open cluster is probably the Pleiades, or Seven Sisters. The Japanese call it the Subaru cluster, and keen observers might recognize its pattern on the Subaru automobile logo. New research shows that the Pleiades and more than 150 other star clusters all originated in only three star-forming regions. Image: By NASA, ESA, AURA/Caltech, Palomar Observatory. http://hubblesite.org/newscenter/archive/releases/2004/20/image/a/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=7805481

Many astronomy-interested people know of the Hyades and the Pleiades. They’re star clusters in the Taurus constellation. They’re two out of a handful of star clusters that are visible to the unaided eye under dark sky conditions.

It turns out that these clusters, along with more than 150 other nearby clusters, all originated in only three massive star-forming regions.

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We’re Now Just Weeks Away from a Stellar Explosion You Can See With Your Own Eyes

Artist's illustration of a nova

I’ve seen some pretty incredible things using my eyes.. First off of course, is the stunning sight of a dark star filled sky, then there is the incredible sight of the Andromeda Galaxy 2.5 million light years away. Planets too can of course be seen as they slowly move across the sky but it’s a little more unusual to see something that reminds us the Universe changes. Well, we have an opportunity  in just a few weeks time. The star T Corona Borealis (T CrB) will brighten about 1,500 times so it can be seen with the unaided eye. Miss it though and you will have to wait another 80 years!

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Sorry Spock, But “Vulcan” Isn’t a Planet After All

This artist's illustration shows the exoplanet Eridani b, aka Vulcan, home of Star Trek's Commander Spock. Unfortunately, evidence is mounting that the planet isn't really there. Image Credit: JPL-Caltech

In 2018, astronomers detected an exoplanet around the star 40 Eridani. It’s about 16 light-years away in the constellation Eridanus. The discovery generated a wave of interest for a couple of reasons. Not only is it the closest Super-Earth around a star similar to our Sun, but the star system is the fictional home of Star Trek’s Vulcan science officer, Mr. Spock.

It’s always fun when a real science discovery lines up with science fiction.

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