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nmfpriv t1_jdwdznw wrote

Why are they analyzing 1b when the priority ones in habitable zone are e, f and g? Obviously 1b is a dead planet that surprises no one

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AlphaDrac t1_jdwfp7n wrote

In order to measure a planet’s atmosphere Webb needs to watch the planet transit it’s star (which provides light that filters through its atmosphere). The wavelengths of filtered light then tell us about the atmosphere (or lack thereof in this case).

This planet just happened to be transiting first, I’m sure they’ll look back and observe the others in the system when it’s their turn.

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karlou1984 t1_jdx07ok wrote

Shouldn't be that long hopefully. I thought the orbital time is like 21 days max for these planets, some a lot shorter.

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AlphaDrac t1_jdy6mhv wrote

You may also have to consider the orbital planes of the planets. Now I really haven’t looked up anything deep about the Trappist system, but it may be like ours where planets orbit on similar planes, but not the same one. So while each orbital period is relatively short, it might take longer to get ones with good alignment between us and their star. Again, that’s just me guessing. I don’t have time to google it right now

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remchien t1_jdya4ce wrote

While usually true, in this case they used MIRI to measure the amount of missing heat when the planet was behind the star as opposed to next to it. A secondary eclipse instead of a transit. They can then make assumptions about the atmosphere with that measured temperature and the fact that it is a tidally locked planet.

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3SquirrelsinaCoat t1_jdwvyaj wrote

TRAPPIST system is a significant point of study - there are loads of brilliant people waiting for this data. Stay tuned. 1b is just a little something to wet your whistle.

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summerissneaky t1_jdzxkly wrote

I think this effectively dried most whistles out there. We shall see.

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gg_account t1_jdx6o50 wrote

Closest planet to star, so most transits, so most data to analyze.

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FTL_Diesel t1_je0d3zh wrote

For two reasons:

  1. The inner-most planets are the easiest to observe. It will be almost impossible to observe e, f, and g in secondary eclipse, though there is a transmission spectrum that has been taken of -1g, and another group has observed -1c in secondary eclipse.

  2. It is an overstatement to say that -1b (or any of the planets) would obviously be a bare rock in space. Indeed, the planning for this observation assumed a roughly Venus-like and cooler atmosphere that would have required all five secondary eclipse observations combined to detect any signal. In the event, the planet is a hot rock, and the eclipse was seen in just the first of those five observations, which was quite surprising!

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Trumpologist t1_je165x4 wrote

Doesn’t this make C unlikely too :/

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FTL_Diesel t1_je16xyc wrote

Not necessarily. It could be that -1c has a Venus-like atmosphere.

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