Space and astronomy news
Astronomers discovered a rocky exoplanet in the habitable zone of Proxima Centauri, the closest star to the Sun. Could there be life there? The European Southern Observatory’s 39-meter Extremely Large Telescope is under construction and expected to be completed in the next few years. Could this mighty observatory see evidence of biosignatures in the reflected light from the planet?
In 2017, a worldwide collection of radio telescopes gathered data about the event horizon around the supermassive black hole at the heart of M87. This was the first time we saw the shadow of a black hole. One year later, the Event Horizon Telescope, including the new Greenland Telescope, came together again. Today, we got the updated 2018 image showing that a bright spot in the ring has shifted by 30 degrees compared to the 2017 image.
Researchers have developed the first 3D maps of magnetic field structures within a spiral arm of the Milky Way. While we’ve seen smaller-scale magnetic fields before, this is much larger, showing the overall magnetic pattern in our galaxy. These fields are incredibly weak, about 100,000 times weaker than the Earth’s magnetic field, but they impact the galaxy, strongly influencing star-forming regions.
Astronomers measure the Universe’s expansion rate and have found a discrepancy between the speed nearby versus the speed measured in the Cosmic Microwave Background. This is known as the Hubble Tension, and the search is on for anything that could explain it. One possible explanation is measurement error, which causes the Cepheid variables in galaxies to be too close together, obscuring results. New observations from JWST have removed this as an explanation.
Astronomers have found examples of giant galaxy clusters dozens of times larger than the Milky Way with all the raw materials for star formation, but they haven’t gotten going yet. NASA’s Chandra and other telescopes found regions of gas blazing in x-ray radiation between 3.4 and 9.9 billion light-years from Earth. The total mass of the gas outweighs all the stars typically found in hundreds of galaxies in galaxy clusters.
The 30 Dor B star-forming region is one of the most dramatic places in the Universe. It is located in the Large Magellanic Cloud, about 160,000 light-years from Earth, and is home to some of the most massive stars ever seen. It’s been forming stars for the last 8-10 million years, the largest of which have detonated as supernovae, hurling material and seeding even more stars. A new image from Chandra has identified the remnants from at least two supernovae in the nebula.
Neutron stars are the incredibly dense remnants from massive star supernovae. Although they’re pulled into dense spheres by their intense gravity, it’s believed that neutron stars could have slight deformations, known as “mountains,” caused by crustal strains and interactions with magnetic fields. If the mountains are there, merging neutron stars should slightly distort the signal received by gravitational wave observatories.
In the search for life, astrobiologists have proposed that various chemicals, like methane, could be potential biosignatures. But a new study suggests that missing chemicals might make an even stronger case there’s life in the world. For example, if a terrestrial planet has much less carbon dioxide in its atmosphere than other planets in the same system, life could cause the difference. Fortunately, this is the kind of signal JWST could search for.
When a star with several times the mass of the Sun dies in a supernova explosion, it ends up as a neutron star, compressing its protons and electrons into neutrons. But neutron stars have layers, and the most massive ones there might have a core made of an even denser material called “deconfined quark matter.” A new supercomputer simulation predicts that the most massive neutron stars almost certainly have these quark-matter cores.
Primordial black holes are one explanation for dark matter, although it’s not widely accepted. These black holes would have formed at the beginning of the Universe and would be at least the mass of a medium-sized asteroid. These black holes may have fallen into the stars if they are out there. These low-mass black holes would emit Hawking radiation, contributing to the star’s radiation pressure. Is there a way we could know if there’s a black hole inside the Sun?