cross-posted from: https://dubvee.org/post/1964912

> Black hole jets, which spew near-light-speed particle beams, can trigger nearby white dwarf stars to explode by igniting hydrogen layers on their surfaces. "We don't know what's going on, but it's just a very exciting finding," said Alec Lessing, an astrophysicist at Stanford University and lead author of a new study describing the phenomenon, in an ESA release. Gizmodo reports: > > In the recent work -- set to publish in The Astrophysical Journal and is currently hosted on the preprint server arXiv -- the team studied 135 novae in the galaxy M87, which hosts a supermassive black hole of the same name at its core. M87 is 6.5 billion times the mass of the Sun and was the first black hole to be directly imaged, in work done in 2019 by the Event Horizon Telescope Collaboration. The team found twice as many novae erupting near M87's 3,000 light-year-long plasma jet than elsewhere in the galaxy. The Hubble Space Telescope also directly imaged M87's jet, which you can see below in luminous blue detail. Though it looks fairly calm in the image, the distance deceives you: this is a long tendril of superheated, near-light speed particles, somehow triggering stars to erupt. > > Though previous researchers had suggested there was more activity in the jet's vicinity, new observations with Hubble's wider-view cameras revealed more of the novae brightening -- indicating they were blowing hydrogen up off their surface layers. "There's something that the jet is doing to the star systems that wander into the surrounding neighborhood. Maybe the jet somehow snowplows hydrogen fuel onto the white dwarfs, causing them to erupt more frequently," Lessing said in the release. "But it's not clear that it's a physical pushing. It could be the effect of the pressure of the light emanating from the jet. When you deliver hydrogen faster, you get eruptions faster." The new Hubble images of M87 are also the deepest yet taken, thanks to the newer cameras on Hubble. Though the team wrote in the paper that there's between a 0.1% to 1% chance that their observations can be chalked up to randomness, most signs point to the jet somehow catalyzing the stellar eruptions.

> Black holes the size of an atom that contain the mass of an asteroid may fly through the inner solar system about once a decade, scientists say. Theoretically created just after the big bang, these examples of so-called primordial black holes could explain the missing dark matter thought to dominate our universe. And if they sneak by the moon or Mars, scientists should be able to detect them, a new study shows.

> Observations with the LOFAR (Low Frequency Array) radio telescope last year showed that first generation Starlink satellites emit unintended radio waves that can hinder astronomical observations. New observations with the LOFAR radio telescope, the biggest radio telescope on Earth observing at low frequencies, have shown that the second generation ’V2-mini’ Starlink satellites emit up to 32 times brighter unintended radio waves than satellites from the previous generation, potentially blinding radio telescopes and crippling vital research of the Universe.

cross-posted from: https://rss.ponder.cat/post/16484

Source

As always with these news it is still too early to draw conclusions: more analysis and tests are necessary.

https://www.nasa.gov/missions/mars-2020-perseverance/perseverance-rover/nasas-perseverance-rover-scientists-find-intriguing-mars-rock/

I was about 30 years old when I talked to my mother about some program on TV about astronomy when she mentioned that our sun is a star. It's like all the other stars we see during the night, it's just closer to us so it appears bigger. My mind was blown. I didn't understand how I could have lived for 30 years and never thought this thought.

Yesterday me and our 10 years old were talking about the universe and things in it, and I mentioned to her that our sun is just a star like all the other ones we see during the night. I saw that her mind was as blown as mine was back when my mom told me this fact.

Actually even in the song "Twinkle twinkle little star, how I wonder what you are." it encourages us to think about this fact, but it took me 30 years to do so.

A group of astronomers want to change the definition of a planet. Their new proposed definition wouldn't bring Pluto back into the planetary fold, but it could reclassify thousands of celestial bodies across the universe. From a report:

> The International Astronomical Union's (IAU) current definition of a planet, established in 2006, includes only celestial bodies that are nearly round, are gravitationally dominant and orbit our Sun. This Sun-centric definition excludes all of the bodies we've discovered outside our solar system, even if they may fit all other parameters. They are instead considered exoplanets. Those behind the new proposal critiqued the IAU's definition in an upcoming paper in the Planetary Science Journal, arguing it's vague, not quantitative and unnecessarily exclusionary.

Their new proposal would instead classify planets based on their mass, considering a planet to be any celestial body that:

1. orbits one or more stars, brown dwarfs or stellar remnants and,
2. is more massive than 10ÂÂ kilograms (kg) and,
3. is less massive than 13 Jupiter masses (2.5 X 10^28Âkg).

The planet Jupiter is particularly known for its so-called Great Red Spot, a swirling vortex in the gas giant's atmosphere that has been around since at least 1831. But how it formed and how old it is remain matters of debate. Astronomers in the 1600s, including Giovanni Cassini, also reported a similar spot in their observations of Jupiter that they dubbed the "Permanent Spot." This prompted scientists to question whether the spot Cassini observed is the same one we see today. We now have an answer to that question: The spots are not the same, according to a new paper published in the journal Geophysical Research Letters.

From the other place: https://www.reddit.com/r/space/comments/1dmibwd/this_is_my_most_advance_moon_photograph_ever_it/

Pics too good to miss. :)

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Another interesting video from Scott Manley.

cross-posted from: https://lemmy.sdf.org/post/18298626

> "I recently explored the optimal fuel burn schedule to land as gently as possible and with maximum remaining fuel. Surprisingly, the theoretical best strategy didn’t work. The game falsely thinks the lander doesn’t touch down on the surface when in fact it does. Digging in, I was amazed by the sophisticated physics and numerical computing in the game. Eventually I found a bug: a missing “divide by two” that had seemingly gone unnoticed for nearly 55 years."