“Recent” Astronomical Phenomena
An astronomical event such as the 1054 supernova would not be considered a recent event by human standards. But when compared to our ancient and ever-expanding universe, even astronomical events that occurred millions of years ago are considered recent. But for our purposes in this week’s blog, I am going to consider the human perception of recent. I am going to detail a few astronomical events have happened in recent history.
V838 Monocerotis
The image above shows V838 Monocerotis which is a variable star approximately 20,000 light-years from Earth in the Monoceros constellation. Variable stars are different from other stars in that their brightness as it is seen from Earth varies. This means the star’s apparent magnitude(brightness) has been altered even by a small amount. The unusual halo of light surrounding the star is called a light echo and is made of interstellar dust like a nebula. Because light and sound have the same wave properties, light can echo similar to the way sound does. Light from V838 Mon was reflected off the interstellar dust which allowed observers on Earth to see a spectacular burst of light from the star in 2002. V838 Monocerotis became 600,000 times brighter than the Sun in January of 2002 and eventually faded in April of the same year. The burst of light revealed previously concealed parts of the dust cloud’s structure. Scientists have continued to study the structure of the cloud using the light echo and the Hubble Space Telescope years after 2002. The cause of the burst is still unclear and despite being like other phenomena like supernovae but too many differences remain.
AT2020mrf Supernova
The AT2020mrf Supernova is the fifth addition to an entirely new classification of supernova called “Cow”. The first supernova of this type’s name was randomly generated as AT2018cow which also gave rise the classification’s unusual name. Cow supernovae are massive explosions of giant stars that either result in a black hole or neutron star. The cow supernova is also different from other supernovas in that mass is ejected prior to the explosion and later glows because of impact with the shock wave. AT2018cow appeared ten times brighter than a standard supernova and faded much quicker. The most recent cow supernova AT2020mrf was initially found in 2020 and was reportedly 10,000 times brighter than a standard supernova in the X-ray. According to graduate of Caltech, Yuhan Yao, the cores that result from these events are highly active cores, exposed, and have high levels of X-ray emissions. Yao believes that the data from the AT2020mrf gives us more information about whether the center of the supernova’s source of power is a black hole or a neutron star. The image directly above this section illustrates the visual difference between a cow supernova and a “normal supernova”.
GRB221009A Gamma-Ray Burst
A gamma-ray bursts are immensely energy heavy explosions that are caused by supernovae, collisions between two neutron stars, two black holes, and/or a black hole and a neutron star. The most recent gamma-ray burst detected was the GRB221009A on October 9th, 2022. Shortly after the burst was detected two research teams quickly assembled to collect data on the burst using the Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and the Wind spacecraft. It is believed that this burst was triggered by a collapsed star and eventual supernova. According to Jillian Rastinejad, a PhD student from Northwestern University,
“In our research group, we’ve been referring to this burst as the ‘BOAT’, or Brightest Of All Time, because when you look at the thousands of bursts gamma-ray telescopes have been detecting since the 1990s, this one stands apart”
The burst originated 2.4 million light-years from Earth in the direction of the constellation Sagittarius. It appears as a small red dot at the center of the image above. Researchers also state that the highly energetic GRB221009A burst gives them insights on how heavy elements are made as a result of star collapse.
What’s Next
As my project comes to a close, I will be tying up some loose ends about the Crab phenomena and finally including those interviews I have been promising. Thank you for reading and see you next week!
References
Blue, C. (2022, October 14). Record-Breaking Gamma-Ray Burst Possibly Most Powerful Explosion Ever Recorded. Noir Lab. https://noirlab.edu/public/news/noirlab2224/
Calvin, W. (2022, January 10). Astronomers Find Most Luminous “Cow” to Shine in X-Rays. Caltech. https://www.caltech.edu/about/news/astronomers-find-most-luminous-cow-to-shine-in-x-rays
Hubble’s Latest Views of Light Echo From Star V838 Monocerotis. (2022, October 26). Hubble Site. https://hubblesite.org/contents/media/images/2006/50/2005-Image.html
V838 MONOCEROTIS. (2004, March 4). Hubble Site. https://hubblesite.org/contents/media/images/3867-Image?Tag=Reflection%20Nebulas&filterUUID=6b40edb4-2a47-4f89-8047-2fe9359344f3
