Starship Asterisk*

BillT wrote:
Anyone know the orbital period of each planet? I saw a range from 1.5 to 12 days mentioned but not the individual period of each planet. I'm wondering how stable the arrangement is.

neufer wrote:

---

I noticed all the planets seem to be in a 3:2 resonance
with their neighboring planets a la Pluto/Neptune.

Does that mean that their elliptical

• orbits are all set up such that:
  
  each outer/inner planet is
  near aphelion/perihelion

at inferior conjunction.

Fred the Cat wrote:Any chance they could be named after the seven dwarfs with the sun representative of Snow White's ruby lips?

• Down with dwarfism in Astronomy!
  Replanetize Pluto!
  Dedwarf the Sun!

Jim Armstrong wrote:"in the Asterisk logo?"?
I hope I got that. (P.S.: Nope, missed it)
"they orbit very close to their faint, tiny star they could also have regions where surface temperatures allow for the presence of liquid water, a key ingredient for life."

I have suggested before that the life subject should be discussed here as "life as we know it" or "life as it exists on Earth."
I am not prepared to claim that I somehow know what is necessary for life.

This is an exciting discovery.

BDanielMayfield wrote:

Fred the Cat wrote:Any chance they could be named after the seven dwarfs with the sun representative of Snow White's ruby lips?

please nooooo.

Respectfully, I must disagree. I just can't take it anymore! First came the calling of all main sequence, normal stars dwarfs. Then the demotion of Pluto to dwarf planet status. At least 4 of these newly discovered worlds are larger than the Earth. Please don't encourage the continuation of this trend toward deminishment.

• Down with dwarfism in Astronomy!
  Replanetize Pluto!
  Dedwarf the Sun!

Bruce, the anti-dwarfite

rstevenson wrote:So Bruce, you're saying we should just toss the idea of dwarfism?

Rob

neufer wrote:I noticed all the planets seem to be in a 3:2 resonance
with their neighboring planets a la Pluto/Neptune.

eurorusty wrote:With such a tight packing, I would guess tidal forces would be significant. I think we could expect one or more planets to exhibit global volcanism like Io does in the Jovian system. Will see if I can write a simulator to confirm what the forces will be!

• Strong interplanetary tides.
  Leftover heat from relatively recent accretion.
  More radioactive elements which haven't had enough time to decay yet.

eurorusty wrote:
With such a tight packing, I would guess tidal forces would be significant. I think we could expect one or more planets to exhibit global volcanism like Io does in the Jovian system. Will see if I can write a simulator to confirm what the forces will be!

neufer wrote:Io heats up pretty good with a period of 1.77 days (despite an eccentricity of just 0.0041).

Since tidal forces scale inversely with period squared
(and tidal heating probably scales inversely with period to the fifth power )
one might assume that TRAPPIST-1b (with a period of just 1.51 days) heats up pretty good tidally.

Note, however, that tidal heating drops off very rapidly [R^-(15/2) maybe] with orbital distance.

BDanielMayfield wrote:Is Io's orbit eccentricity (small though it is) the main cause of its heating? How much of Io's heat is caused by the continuously changing distances between Jupiter's large moons?

Chris Peterson wrote:

BDanielMayfield wrote:
Is Io's orbit eccentricity (small though it is) the main cause of its heating? How much of Io's heat is caused by the continuously changing distances between Jupiter's large moons?

All of Io's tidal heating is the result of its changing distance from Jupiter over its orbit, because of its non-zero eccentricity. The only effect of the other moons is in preventing Io's orbit from becoming circularlized over time.

neufer wrote:

Chris Peterson wrote:

BDanielMayfield wrote:
Is Io's orbit eccentricity (small though it is) the main cause of its heating? How much of Io's heat is caused by the continuously changing distances between Jupiter's large moons?

All of Io's tidal heating is the result of its changing distance from Jupiter over its orbit, because of its non-zero eccentricity. The only effect of the other moons is in preventing Io's orbit from becoming circularlized over time.

A while back I ran the numbers on this and
(on my second attempt ) proved this to be the case.

geckzilla wrote:
Anyone know if orbital resonance prevents things like double stellar transits happening from the vantage point of, say, the third or fourth planets? I'm guessing the chance goes up by the fifth, six, and seventh, but I'm not sure.

• c observes 9 transits of b
  d observes 6 transits of c
  e observes 3 transits of d
  f observes 2 transits of e
  g observes 1 transit of f

• 1) that planets e through g regularly observe double stellar transits
  2) or that things are so aligned that none of the planets ever observes a double stellar transit.

geckzilla wrote:
I've been toying around with a reasonably accurate simulation I've got set up in Blender, and all I know is that each planet seems to be in the wrong place to make the observation each time two of the others form in syzygy with the star. My simulation is unfortunately keyframe animated and I doubt its accuracy after copy and pasting each orbit over and over. Rounding errors build up. It only runs for 100 Earth days currently.

• 1) Do the planet's initial relative positions return after 36.15 days?
  
  2) How do you set the planet's initial relative positions?
  
  3) How do you set Blender?
  (grate, blend, shred, grind, mash, liquefy, frappe, stir, beat, puree, chop, whip, pulse, ice crush?)