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Py4Phy / project-trappist-system

Project 2 for the 2017 class (including solution)
MIT License
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gather data for TRAPPIST-1 system #1

Closed orbeckst closed 7 years ago

orbeckst commented 7 years ago

We need data for

Sources

ianmkenney commented 7 years ago

92bb1665f2cb1be0cd1fc801307a440c2eaf178f should take care of what we need... Some data was missing, but I'm sure nobody will be offended if we ballpark it. I have the raw data in YAML format and have the processed data (in SI) inside the notebook as a dataframe. Depending on how we want to move forward, we can convert the dataframe to what we need.

orbeckst commented 7 years ago

Nice. But is the star ("sun") really much lighter than the planets??? https://github.com/ASU-CompMethodsPhysics-PHY494/project-snowwhite-7dwarves/blob/master/data/bodies.yaml#L2

ianmkenney commented 7 years ago

The multiplier would be the suns mass. Take a look at the notebook, it should be more clear.

On Feb 26, 2017, at 11:36 AM, Oliver Beckstein notifications@github.com wrote:

Nice. But is the star ("sun") really much lighter than the planets??? https://github.com/ASU-CompMethodsPhysics-PHY494/project-snowwhite-7dwarves/blob/master/data/bodies.yaml#L2

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orbeckst commented 7 years ago

For the project we want to use consistent units. The commonly used ones are astronomical units where mass is in mutiple of our sun's mass (TRAPPIST1 and all planets), distances are in AU (mean earth-sun distance) – see current HW. Time should be 1 solar year as base units… I think.

Can you convert all to AU?

For the missing ones, can you suggest values?

On 26 Feb, 2017, at 12:19, Ian Kenney notifications@github.com wrote:

The multiplier would be the suns mass. Take a look at the notebook, it should be more clear.

-- Oliver Beckstein orbeckst@gmx.net skype: orbeckst orbeckst@gmail.com

ianmkenney commented 7 years ago

So you want the masses of ALL bodies in terms of our sun's mass?

ianmkenney commented 7 years ago

I updated the values in the notebook for consistency, I don't know of any values that would work offhand and no real guidance was offered from the letter. Should we play around with values such that we find some sort of stability?

orbeckst commented 7 years ago

Yes, I think that's the best approach. We can even make it an additional bonus problem to explore additional mass ranges. For a start, if the star is a bit heavier than jupiter and there's no big impact of the planets on its movement then it's probably a good guess that these unknown masses are much less than the star's mass.

On 27 Feb, 2017, at 12:13, Ian Kenney notifications@github.com wrote:

I don't know of any values that would work offhand and no real guidance was offered from the letter. Should we play around with values such that we find some sort of stability?

-- Oliver Beckstein orbeckst@gmx.net skype: orbeckst orbeckst@gmail.com

orbeckst commented 7 years ago

I think we're just going to ignore the 7th planet with missing data.

Otherwise looks great – see notebook!