Jump to content

alfa015

Members
  • Content Count

    11
  • Joined

  • Last visited

Community Reputation

0 Neutral

About alfa015

  • Rank
    Quark

Profile Information

  • Favorite Area of Science
    Astronomy

Recent Profile Visitors

719 profile views
  1. The massive planet, which shouldn't exist based on current theories, is prompting astronomers to revisit their models for planetary formation. Astronomers have discovered a gigantic planet orbiting a puny star some 30 light-years away. And according to current theories, the planet shouldn’t exist. Dubbed GJ 3512 b, the gas giant is at least half the mass of Jupiter. But it orbits a red dwarf star that’s just one-tenth the mass of our Sun. "Around such stars there should only be planets the size of the Earth or somewhat more massive Super-Earths," said Christoph Mordasini of the University of Bern in a press release. "GJ 3512 b, however, is … at least one order of magnitude more massive than the planets predicted by theoretical models for such small stars." Scientists thought that gas giants like Jupiter always started their lives by developing heavy, solid cores before quickly accumulating thick, gassy atmospheres. That’s what current models predict. But because of this new planet’s unusual heft compared to its host star, the new research suggests that’s not always the case. The discovery is important because red dwarfs are thought to be the most common stars in the universe, accounting for roughly 75 percent of all stars. And typically, red dwarfs only have a few petite planets. This is because small stars shouldn't have enough extra material left over from their formation to build large planets. The planets found around red dwarfs typically range from about the mass of Earth to roughly the mass of Neptune. But they almost never approach the mass of Jupiter, like GJ 3512 b does. (For reference, Jupiter is about 300 times the mass of Earth and 20 times the mass of Neptune.) Because GJ 3512 b is such a big fish in a little pond, the researchers say its host star shouldn't have had enough material to form the gas giant in the first place — at least according to current models. So, simply the existence of GJ 3512 b is making researchers reconsider whether gas giant planets really must start their lives as nascent embryos of heavy particles before gobbling up copious amounts of gas (a process called core accretion). “One way out would be a very massive disk that has the necessary building blocks in sufficient quantity,” said planet-formation expert Hubert Klahr from the Max Planck Institute for Astronomy (MPIA) in a press release. The basic idea is that if the star GJ 3512 initially started its life surrounded by a particularly massive disk of both gas and dust, the gravity of the disk itself would be strong enough to trigger instabilities within it. Some regions of the disk would then directly collapse, ultimately forming large planets without undergoing the typical two-stage growth process. This is called the gravitational disk collapse model, and so far, it's been largely ignored when it comes to planets around red dwarfs. The major issue with this scenario is that researchers haven't yet found examples of such oversized disks around young red dwarf stars. But according to the study, the gravitational collapse scenario is the most logical way a planet as large as GJ 3512 b could have formed around a star so small. And the case for gravitational collapse is made even more compelling by the fact that the astronomers also found evidence for a second large planet much farther out in the system — as well as hints that a third massive planet might have been ejected from the system long ago. “With GJ 3512 b, we now have an extraordinary candidate for a planet that could have emerged from the instability of a disk around a star with very little mass," said Klahr. "This find prompts us to review our models.” The new research was published Thursday in Science. Source: https://astronomy.com/news/2019/09/giant-planet-found-around-tiny-star-defies-expectations
  2. As of September 2019, these are the 5 potentially habitable exoplanets closer to Earth: Source: http://www.youtube.com/watch?v=GK6owRTFz0Q 1.GLIESE 273 b Gliese 283 b orbits the red dwarf star Luyten, located 12 light years away. - The exoplanet is 84% similar to Earth. - It has an orbital period of 18.6 days. - A minimum mass 2 times higher than Earth. - An average radius 40% higher. - And an equilibrium temperature of 11 degrees more. 2. TEEGARDEN b Teegarden b orbits the red dwarf star Teegarden, 12 light years away. - The exoplanet is 95% similar to Earth. - It has an orbital period of 5 days. - A minimum mass and average radius only 5% higher than Earth. - And an equilibrium temperature of 9 degrees more. 3. GLIESE 1061 c Gliese 1061 c orbits the red dwarf star Gliese 1061, 12 light years away. - The exoplanet is 88% similar to Earth. - It has an orbital period of 6.7 days. - A minimum mass 75% higher than Earth. - And an equilibrium temperature of 20 degrees more. 4. TAU CETI e Tau Ceti e orbits the solar-type star Tau Ceti, 12 light years away. - The exoplanet is 74% similar to Earth. - It has an orbital period of 163 days. - A minimum mass 3 times higher than Earth. - An average radius 60% higher. - And an equilibrium temperature of 30 degrees more. 5. PROXIMA B Finally, Proxima b orbits the red dwarf star Proxima Centauri, 4.2 light years away. - The exoplanet is 87% similar to Earth. - It has an orbital period of 11 days. - A minimum mass 30% higher than Earth. - An average radius 10% higher. - And an equilibrium temperature of 28 degrees less. To which of these exoplanets would you go to? why?
  3. Anybody interested? Btw I was recently interviewed by Tony Darnell from Deep Astronomy:
  4. Hi all! We are looking for more observatories and amateur astronomers who might want to join the project. The Habitable Exoplanet Hunting Project is a worldwide network of amateur astronomers searching for new potentially habitable exoplanets. I am coordinating over 20 observatories located in 5 continents. We are searching for habitable exoplanets around non-flare G, K and M-type stars located within 100 ly. The stars we are monitoring already have known transiting exoplanets, but none of them are potentially habitable. We are monitoring each star 24/7 for several months. By doing so, we believe that the chances of finding an exoplanet increase for particular targets. Moreover, we are focusing on stars closer than 100 light years because, on the one hand, the closest habitable exoplanets will be the first destinations of interstellar missions and, on the other, because very few nearby habitable exoplanets around G and K-type stars have been discovered: only 2 of them. The number of potentially habitable exoplanets that we could discover is, in theory, around 25. This calculation was obtained by taking into account the number of non-flare stars within 100 light years and the percentage of them that should show transits in the habitable zone. Each observatory observes the same star and, when the transit of a hypothetical habitable exoplanet becomes unlikely, we move to another star. Within 100 light years, we only found 10 non-flare G, K and M-type stars with known transiting exoplanets not potentially habitable. Big telescopes are not necessary, but CCD cameras with a resolution of at least 16 bits are advisable because we are searching for exoplanets that produce a change of brightness in the star of around 0.1%. If you are interested, feel free to contact me. More info: https://youtu.be/0A7gEaewOws
  5. Hi! I would like to share with you guys some facts you might not know about antimatter: 1º - Recent studies suggest that an antimatter spacecraft could achieve up to 70% the speed of light, reaching Proxima b in just about 6 years. 2º - The maximum time that antimatter has been stored is 405 days. 3º - According to the former Fermilab physicist Gerald Jackson, antimatter rockets could become a reality by 2050. Source: https://www.youtube.com/watch?v=IIgpTrmKUZs&list=PL3RiFKfZj3ptaxqH3te_eKz1ge_CxQxjw&index=1 What are your thoughts about antimatter propulsion?
  6. Aww, alright, then, may I share the instructions on how to use the project by showing this from instructables?: url deleted
  7. Hi there! I would like to share with you my video on how to find exoplanets from home. I won't share the link because the moderators do not allow me to do it, but the video is embedded here: Link removed To those familiar with the project, I suggest you to skip to the minute 2:00[/font][/color] What do you think about it? have you already found an exoplanet?
  8. Hi there! I would like to share with you my video on how to find exoplanets from home: video link removed by moderator To those familiar with the project, I suggest you to skip to the minute 2:00 What do you think about it? have you already found an exoplanet?
  9. My apologies, try this one: Ah alright! Interesting your question! mmmm well, according to the the paper of the discovery, 'several studies have shown that planetary magnetic fields in tidally locked planets can be strong enough to prevent atmospheric erosion by stellar magnetic fields and flares': http://www.nature.com/nature/journal/v536/n7617/full/nature19106.html Mercury for example has magnetic field, but too weak for it's proximity to earth. I think we would need to know how strong are the flares of Proxima Centauri (considering the distance between the star and the exoplanet) and how strong is the magnetic field of Proxima b. Thank you for the advice, I will try to speak slower in my next video Cheers.
  10. Hi! I would like to share with you guys my brief analysis on the exoplanet Proxima b (first part is introduction to the main features of the planet and my opinion starts in the minute 1:20) - http://bit.ly/2oQJDqd What do you think about Proxima b and about my points? I'm sure you know much more about it than me. Cheers!
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.