TESS Thread

[Gargamel]

TESS is launching soon, and I'm psyched.   Similar to Keplar, but instead on focusing on one area of the sky, TESS will scan local stars, revealing candidates that our more conventional telescopes have a chance of gleaning more info on. 

https://tess.gsfc.nasa.gov/

Being a member of the Zooniverse, in particular the Keplar mission, I'm really excited to see the data that comes back from this. 

 

[Scotius]

And there should be a LOT of data Kepler scanned just a tiny slice of the sky, and extrasolar planets already count in the thousands. How much more TESS will help to locate? How many of them will be Earth-like? Exciting! Still, a proper, sturdier replacement for Kepler observatory is in order. TESS is more like a crutch.

[Spaceception]

I can't wait! Launch scheduled for tomorrow. I really hope we get some new, really cool Earth-like planets to study. Especially ones close to Earth so they're easier to study. I wonder how many there are within 20 light years of us.

[Canopus]

Certainly the most interesting payload launched by a Falcon yet.

[Gargamel]

Delayed!

https://www.space.com/40322-spacex-nasa-tess-exoplanet-mission-launch-delay.html

[NSEP]

On 15-4-2018 at 4:18 PM, Canopus said:

Certainly the most interesting payload launched by a Falcon yet.

Pretty much all NASA payloads are quite interesting.

[YNM]

4 minutes ago, NSEP said:

Pretty much all NASA payloads are quite interesting.

I guess it's also interesting trajectory.

[Wjolcz]

On 13/04/2018 at 10:29 AM, Scotius said:

And there should be a LOT of data Kepler scanned just a tiny slice of the sky, and extrasolar planets already count in the thousands. How much more TESS will help to locate? How many of them will be Earth-like? Exciting! Still, a proper, sturdier replacement for Kepler observatory is in order. TESS is more like a crutch.

Kepler looked much farther though. Tabby's star (the farthest star studied by Kepler I know of) was over 1000 ly iirc. Tess will scan as far as 500 ly? It's still the whole sky though.

[Gargamel]

16 hours ago, Wjolcz said:

Kepler looked much farther though. Tabby's star (the farthest star studied by Kepler I know of) was over 1000 ly iirc. Tess will scan as far as 500 ly? It's still the whole sky though.

But that's the whole point of TESS.

The nits will correct me here, as I know I am wrong on the exact numbers, but the concepts are sound:

Keplar covered an area roughly the size of your thumb at arms length.  Ie, a very VERY small patch of sky, and looked very deep into it.  

TESS will cover almost the entire sky, at a much shorter range, but all of it's detections will be close enough that larger telescopes can then zoom in on the locations to see what they're about. 

 

[Scotius]

Which leads me to conclusion, that TESS should be renamed "Argus" - in honor of the hundred-eyed, all-seeing titan from the Greek mythology

[YNM]

8 hours ago, Gargamel said:

Keplar covered an area roughly the size of your thumb at arms length.  Ie, a very VERY small patch of sky, and looked very deep into it.  

Not for K2 though.

Also, Kepler's CCD is massive.

TESS have larger FoV still.

But then, TESS is a "cheap" mission, unlike Kepler - so expect slightly less resolution.

Edited April 21, 2018 by YNM

[Spaceception]

@YNM Judging by that picture, am I correct in assuming we should expect to only find potentially habitable planets, and other long period planets around the dark blue, green, orange and red area's? Or at least the majority of them? And the light blue, and brown area's would be red dwarf planets and hot Jupiters mostly?
With like a handful of chance transits for long period planets too in the light blue and brown area's.

Edited April 21, 2018 by Spaceception

[YNM]

@Spaceception I think length of continuous observation only affects the probability of finding a pattern. Kind of like if you fish every day compared to every week, or every day but every other week.

[VaPaL]

@YNM you known why it won't scan the ecliptic plane?

[YNM]

2 hours ago, VaPaL said:

... why won't it scan the ecliptic plane?

Moon ? Earth ? Sun ?

[Gargamel]

10 hours ago, YNM said:

Not for K2 though.

Bah, that's just cause the camera wobbles too much!   *D    But joking aside, that's still a tiny patch compared to TESS.

 

 

And for those that haven't, you should join up at Zooniverse.org, and start help sifting through the K2 data, you can find yourself a planet or 4 there if you work hard enough.  I know I've found a few. 

[YNM]

1 hour ago, Gargamel said:

that's still a tiny patch compared to TESS.

At a freaking high resolution - 94 MP for a small patch compared to 4x 16.4 MP that goes 90 degrees up and down.

But I have to admit, TESS is probably going to get more meaningful results, as the stars detected would be closer by. I just hope we don't get a "visual binary".

[Gargamel]

11 minutes ago, YNM said:

I just hope we don't get a "visual binary".

What's wrong with that?  Take a look at the K2 data I linked above, try doing some interpretations yourself.  The data algorithms include for the possibilities of binaries, easily distinguishing them from transits.  

At the very least, it would throw up a "Hey! look over here! There's something interesting over here!" flag. 

[YNM]

37 minutes ago, Gargamel said:

What's wrong with that?

I don't mean an actual binary. Chance-of-alignment and such is the one I meant.

[Gargamel]

14 minutes ago, YNM said:

I don't mean an actual binary. Chance-of-alignment and such is the one I meant.

Gotcha!

Again, take a look at the data sets the K2 project has released for public interpretation.  Basically, they are looking for periodic dips in brightness.  A star passing behind another such that it represents a binary system would give a one time dip in brightness, or a cyclic one if the passing is due to parallax.  Both of which are accounted for. 

But that's why a good portion of the K2 data interpretation is being done via crowd sourced science.  In some aspects, the Human Eye Mk1 is far better at detecting certain patterns than a computer.  The computers sort through all the data and flag any potential candidates, and then the crowd looks at the candidates and votes yay or nay.   They never expected to have the number of candidates like they did, so they had to turn to crowd sourcing.  

A binary star system, in any form we are discussing, if it gives a periodic dip in brightness would produce a sine wave brightness curve: (From the K2 data set itself): Sorry that's for a variable star.

A 'normal' star produces a flat light curve, and when a planet passes in front of it, gives a sharp clear dip in the data points, on a regular schedule:

 

A binary system, has a 'lift' on each side of the transit, as the detector would now see an increase in light output on either side of the dip right before and after the eclipse, and then a drop below mean output as the stars separate visually:

But if the binary system does not separate enough for the sensor to see they are two stars, you'll get a curve like this.  There is a slight rise above the mean before each eclipse, and the dips are wider than a planet. 

 

 

And for S&G's, here's what a Variable star does look like:

 

 

 

 

[YNM]

@Gargamel I know - I've wrestled with a few of them on Zooniverse and elsewhere as well.

But let's say, a really close alignment of stars. All having massive jupiters. How do you tell which is which ?

I know further observation would iron them out, but just to mention that holding data don't give you full convidence of what is actually going on.

[Gargamel]

4 minutes ago, YNM said:

All having massive jupiters. How do you tell which is which ?

Well it would give really weird results, and those are the types that would make for early candidates for other observation, the whole idea behind the TESS mission! 

[MrTetra]

I only watched a short doc on YouTube last night comparing the 2 with each other. TESS's scanning time frame is seriously impressive. They said it would scan the same patch of sky for 12 days twice in 2 orbits and transmit info back. S. 27 days in total with the orbit it has. They then said anything interesting will be passed to the James Web once its launched for further investigation.  Over the next few years the data recovered will be massive. Exciting times.......

[VaPaL]

17 hours ago, YNM said:

Moon ? Earth ? Sun ?

Yeah, but, you know that they don`t block the whole eclipitic...

[YNM]

6 hours ago, VaPaL said:

Yeah, but, you know that they don`t block the whole eclipitic...

Hmm...

Well, maybe it's for zodiacal effects or something. The Moon also bobs up and down the ecliptic by roughly 5 degrees (at least from Earth).

Edited April 23, 2018 by YNM