Space Engine

Watsisname wrote:

Not all science papers/talks are about the researcher presenting a new discovery, or persuading you that their model of something works and that they understand it and how useful it is for science that they understand it.  In this case the claim is that something is weird with the stellar populations in globular clusters, which is quite inconvenient for our understanding of them, and that all the models that have tried to explain this so far in fact do not work.

I love these kinds of talks. 

DoctorOfSpace wrote:

JackDole wrote:

Source of the post be it through wars or through an irreparably destroyed environment

Common neglect seems unlikely to be a great filter when we are already on the verge of colonizing other worlds.

A more likely great filter may just be reaching technological mastery and peaking with nowhere left to go or nothing left to discover leading to decay.  Dyson swarms may not even be needed to reach this point.

1. In our stellar neighborhood there might be around 130 potentially (p.) habitable exoplanets, 10 of them being Earth-like.
   
2. The closest p. Earth-like planet is called Tau Ceti e, and it is located only 12 light years away from us.
   
3. So far, we have sent a targeted radio message to 2 p. habitable exoplanets, Tau Ceti e and Luyten b. Any reply would be received as of 2037 and 2041, respectively.
   
4. Amateur astronomers have discovered 2 p. habitable exoplanets: LHS-1140 b and K2-288 B b.
   
5. It is possible to detect exoplanets by using a tele-photo lens with an aperture of less than 50 mm.

Stellarator wrote:

Why couldn't this be posted in in the Science & Astronomy Videos channel? Why does this post need a whole separate topic to itself?

A-L-E-X wrote:

Stellarator wrote:

Why couldn't this be posted in in the Science & Astronomy Videos channel? Why does this post need a whole separate topic to itself?

Actually since habitable exoplanets are such a fascinating subject, it might be useful for them to have a topic unto themselves.  Posts in megathreads quickly get buried.   I believe alfa is a professional astronomer who does research in this field.  I like that exoplanets can be detected with a 50mm lens- I didn't know that!  I assume I can do this with my mirrorless EPL-6 camera?

A-L-E-X wrote:

Source of the post Posts in megathreads quickly get buried

alfa015 wrote:

A-L-E-X wrote:

Stellarator wrote:

Why couldn't this be posted in in the Science & Astronomy Videos channel? Why does this post need a whole separate topic to itself?

Actually since habitable exoplanets are such a fascinating subject, it might be useful for them to have a topic unto themselves.  Posts in megathreads quickly get buried.   I believe alfa is a professional astronomer who does research in this field.  I like that exoplanets can be detected with a 50mm lens- I didn't know that!  I assume I can do this with my mirrorless EPL-6 camera?

I think you could.
Here how to do it: https://spectrum.ieee.org/geek-life/hands-on/diy-exoplanet-detector

Watsisname wrote:

Fantastic talk (though a bit more technical than most that I post here) and review of our current understanding of an old astrophysics problem: "Why do some stars explode?"  More precisely, what exactly is going on during the core collapse that allows the ensuing shockwave to reach the star's surface, rather than stall?  If you think this should be trivial, you'd be surprised!

A-L-E-X wrote:

Source of the post Far from being trivial, isn't this how most elements beyond Iron get produced? 

Watsisname wrote:

A-L-E-X wrote:

Source of the post Far from being trivial, isn't this how most elements beyond Iron get produced? 

Actually no, most elements above atomic number 40 came from colliding neutron stars rather than exploding stars.

But what I mean about it not being trivial is the question of how does the star explode?  Most people know that they do, and are familiar with the common explanation for how it happens.  But if you do a naive (or even a very sophisticated) application of physics to explain how it works, you will conclude that the shockwave would stall before reaching the surface.  How a star actually explodes was an astrophysics mystery for many decades.  

What we're finding with the latest high resolution 3D supercomputer simulations is that the physics happening is a lot more complex (and very fascinating), and it turns out that turbulence and huge deviations from spherical symmetry are important, in addition to the momentum transported by the neutrinos (which we suspected, but it wasn't enough), and the structure of the star itself.

To date, Hubble has played the definitive role in the characterization of exoplanet atmospheres. From the first planets available, we have learned that their atmospheres are incredibly diverse. With HST, JWST, and TESS a new era of atmospheric studies is opening up, where wide scale comparative planetology is now possible. Such studies can provide insight into the underlying physical process through comparative studies. Hubble’s full spectroscopic capabilities are now being used to produce the first large-scale, simultaneous UVOIR comparative study of 20 exoplanets ranging from super-Earth to Neptune and Jupiter sizes. With full UV to infrared wavelength coverage, an entire planet’s atmosphere can be probed simultaneously and with sufficient numbers of planets, it will be possible to statistically compare their features with physical parameters. The panchromatic treasury program aims at build a lasting HST legacy, providing the UV and blue-optical exoplanet spectra which will be unavailable to JWST, providing key insights into clouds and mass loss. I will review the highlights of the program to date, which include atmospheric water resolved in emission and new absorption features seen in transmission such as escaping ionized metals. I will also present the latest findings from the ongoing Hubble Treasury program and discuss synergies with JWST.