APOD: Three Worlds for TRAPPIST-1 (2016 May 07)

[neufer]

So, they have MONKS there???

<<The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) is a Belgian optic robotic telescope, which came online in 2010. It is named in homage to the Trappist Order in the Belgian region.

The 48th chapter of the Rule of St. Benedict states "for then are they monks in truth, if they live by the work of their hands". Following this rule, most Trappist monasteries produce goods that are sold to provide income for the monastery. The goods produced range from cheese, bread and other foodstuffs to clothing and coffins, though they are most famous for their beers, which are unique within the beer world, and are lauded for their high quality and flavour. Monasteries in Belgium and the Netherlands, such as Orval Abbey and Westvleteren Abbey, brew beer both for the monks and for sale to the general public. Trappist beers contain residual sugars and living yeast, and, unlike conventional beers, will improve with age. Westvleteren 12 is often considered to be the single best beer in the world.>>

[MarkBour]

PLEASE lose the "artists conception" illustrations. They are rampant nonsense; they ignore physics.
There are "millions" of amazing astro-photos. You don't need invented artwork.
I recommend apod.com to people who can learn the reality. If you keep adding non-scientific artwork, I'll stop recommending this site.

Is anyone else irritated by the lack of realism of the image? The right hand moon is blotting out the light from the sky, even though the moon is much further away, which is obviously impossible.

I believe I see where both of you are coming from, but please consider the following. This is a fantastic astronomical discovery, and will result in a lot of further investigation. APOD could easily have put up an image from TRAPPIST itself, and I think they've had a superb mix of imagery types over time. But these worlds have captured our imagination in alignment with a deep and abiding quest of the human race. To get at that, a luminosity graph will never do. This view, which obviously had to be artist-rendered, is every bit as worthy of our consideration as other APODs. And I see it has sparked a lively discussion in terms of some possible improvements. Actually, the questions it raised for discussion were not so easy. I see one contributor attempted a specific improved picture, and it has drawn as much fire as the original opus.

I want to give the artist some license on the size and ascension/declination of the sister planets ... we could view it as a schematic of the system in that sense. How fun would it be to have just shown 2 dim dots? But I welcome the education from those here discussing some facts of how they must actually be. I see some comments, but I'm not sure how reliable they are. This would take us back to the data that gives detailed information about the orbits insofar as TRAPPIST, or others, have measured them. Again, that just proves that this rendering is a great springboard for discussion and education. I'm wondering how the TRAPPIST-1 system fits with a Titius-Bode rule. It may, or may not. The orbit of 1d seems not to be well determined, yet. Still, the sizes shown in the sky seem possible to me. It should look like a couple of Earths near a Jupiter, right? (https://www.geol.umd.edu/~jmerck/geol21 ... s/04a.html)

[geckzilla]

Still, the sizes shown in the sky seem possible to me. It should look like a couple of Earths near a Jupiter, right?

From a position other than TRAPPIST-1d, yes, one looking significantly larger than the other is possible if you were close enough to it. Like this. Get farther away and you'll get a scene like this. So from 1d, the distance is great enough that the two wouldn't appear so disparate. I toyed around with the system parameters in Blender to see what was possible. You can maximize their size disparity by putting TRAPPIST-1d at its closest possible semi-major axis, having TRAPPIST-1b transit the star and TRAPPIST-1c in conjunction behind the star. 1c will look much smaller than 1b at that point.

[MarkBour]

I toyed around with the system parameters in Blender to see what was possible. You can maximize their size disparity by putting TRAPPIST-1d at its closest possible semi-major axis, having TRAPPIST-1b transit the star and TRAPPIST-1c in conjunction behind the star. 1c will look much smaller than 1b at that point.

Blender is just rendering software, right? It does not help with questions of the possible orbits, does it? You claimed that the planets could never be aligned as shown in the APOD ... specifically that 1c could never appear as a crescent from 1d. Why do you say that?

[geckzilla]

I toyed around with the system parameters in Blender to see what was possible. You can maximize their size disparity by putting TRAPPIST-1d at its closest possible semi-major axis, having TRAPPIST-1b transit the star and TRAPPIST-1c in conjunction behind the star. 1c will look much smaller than 1b at that point.

Blender is just rendering software, right? It does not help with questions of the possible orbits, does it? You claimed that the planets could never be aligned as shown in the APOD ... specifically that 1c could never appear as a crescent from 1d. Why do you say that?

Because distance and scale in space are not intuitive and because I am a visual learner, I use Blender to create a model of the system and simulate how the light from the star illuminates each planet. It's something I started doing some time ago when I realized how wrong my brain had some things. It's a good enough approximation for me to say that yes, that crescent at that position is impossible, given their orbital parameters. The planet would have to be a fraction of its distance from the star for it to appear in crescent phase at that position.

[moonshiner]

an artist's rendering is exponential to envisioning unknown planets. it is a candle piercing the elusive night..a stepping stone from which the intellect builds models and draws conclusions. the experienced mind may thus examine the possibilities based on what is known of planetary science at home..in the solar system.

it may be inferred that planets bound to a red dwarf star continually face the same side to the parent star in the same way that the moon faces the earth. such red dwarf planets endowed with substantial atmospheres would likely have a very distinct weather cycle with an overdrive of storms and lightning.

a hemisphere of a terrestrial red dwarf planet would be continually subject to light and the other hemisphere immersed in eternal night..and possibly eternal cold. a ghastly fierce landscape all year round; probably not the kind that would yield soothing wine and poetry.

[Chris Peterson]

an artist's rendering is exponential to envisioning unknown planets. it is a candle piercing the elusive night..a stepping stone from which the intellect builds models and draws conclusions. the experienced mind may thus examine the possibilities based on what is known of planetary science at home..in the solar system.

Nevertheless, our knowledge of optics and our ability to model real physical systems means that we should expect renderings of astronomical scenes to be physically accurate. That does not preclude the invention of imaginative, speculative scenery. But image scale, color, lighting, shadows, atmospheric effects- these things should be- and can be- accurately rendered.

[MarkBour]

It's a good enough approximation for me to say that yes, that crescent at that position is impossible, given their orbital parameters. The planet would have to be a fraction of its distance from the star for it to appear in crescent phase at that position.

Ah .... at that position. I thought you were saying the outer planet would never see a crescent phase for the inner planets. That's what had me scratching my head.

[geckzilla]

It's a good enough approximation for me to say that yes, that crescent at that position is impossible, given their orbital parameters. The planet would have to be a fraction of its distance from the star for it to appear in crescent phase at that position.

Ah .... at that position. I thought you were saying the outer planet would never see a crescent phase for the inner planets. That's what had me scratching my head.

Oh, heh. Yeah, it'd be far, far, off the picture in crescent phase.

[Fred the Cat]

It's a good enough approximation for me to say that yes, that crescent at that position is impossible, given their orbital parameters. The planet would have to be a fraction of its distance from the star for it to appear in crescent phase at that position.

Ah .... at that position. I thought you were saying the outer planet would never see a crescent phase for the inner planets. That's what had me scratching my head.

Oh, heh. Yeah, it'd be far, far, off the picture in crescent phase.

I was just watching about exoplanets and a video clip pictured a scene like this days APOD. It showed the exoplanet transit then leave the bright disc. There was a moment, just after, when a brief flash came off of the planet's surface. It triggered my mental picture on how we use light from a sun to gather information about the planet - whether it's in our solar system or in one a long ways away.

How you might dissect that flash into small time divisions and analyze it's changing information is pretty mind boggling. If we could ever block the bright star's light to see that flash would be mind altering.