New Earth-sister Kepler 452b announced by NASA

[mfb]

And the Earth was quite quiet in 785 BC.

We still had a lot of oxygen in the atmosphere, which is very reactive and doesn't stay around for long unless nonequilibrium reactions produce it. In addition, the atmosphere has methane and various other chemicals that do not live long in an oxygen-rich atmosphere. Sure, we did not emit radio waves back then, but the atmosphere has been unusual for a very long time.

 

[rootone]

... they used to call Venus Earth's twin before the Venera probes crashed on its' surface.

Actually several of them soft landed and sent back images, though none lasted more than about an hour in the extreme temperature and pressure of Venus' atmosphere.
It wasn't at all what was expected, and the probes just were not built to take that kind of punishment.

 

[castor]

Don't take that literally. Crashed, soft landing, it doesn't really matter.

We really thought Venus might hold some form of life before the Venera probes dispelled that notion.

 

[Raman Choudhary]

How is this name assigned to the star and the planet

http://www.nasa.gov/keplerbriefing0723

As I type this, NASA is announcing discovery of a new planet Kepler 452b that is
- small and (probably) rocky like Earth
- orbits a G2 star
- is in the star's habitable zone
This is the first candidate that meets all three criteria. (Most Earth-twins so far discovered are around tiny red dwarfs, and orbit in a matter of days) It has a 385 day long year, almost exactly the same as Earth.

Kepler 452b is a slightly older sibling of Earth - it has lived in its habitable zone for 6 billion years. It's a little bigger, surface gravity is about 2x Earth, but it probably has a thick atmosphere as well as volcanism.

One implication of this discovery is that these are surely common. We only detect 1 in 50 planets because of alignment issues, so detection of one suggests another 50 out there we can't see with current equipment.

The one imperfection in this otherwise ideal Earth-sister is that it is more than 1300 light years away.

Sir,
How is this name assigned to the star(what's a G2??) and the planet??

 

[rootone]

Stars are classified by luminosity and size.
https://en.wikipedia.org/wiki/Stellar_classification
The star in this system is G class yellow star similar to our sun.

When a new star is registered it is the 'a' object for that system.
Second and subsequent objects found in the same system are denoted 'b' 'c' and so on.

 

[castor]

How is this name assigned to the star and the planet

Sir,
How is this name assigned to the star(what's a G2??) and the planet??

It's a part of the Hertzsprung-Russell classification or the Morgan-Keenan of stellar bodies, depending on their heat output from what I understood. Depending on their surface temperatures, stars are labelled O, B, A, F, G, K, and M in the decreasing order. Therefore, the hottest stars are O-type stars (which usually are extremely massive blue supergiants) to M stars (which are red stars). M stars are the most common type of star, and the O types are the rarest.

Our Sun is a G-type star. In addition to the alphabet G, the numeral 2 indicates the temperature of the star relative to the other classifications. That is, how close the star is to the next classification. The numerals range from 0 to 9, with 0 being the hottest and 9 being the coolest. Therefore, a G0 star which has nearly the same temperature as an F9 star.

Our Sun is a G2 type star, and so is Kepler-452.

The name Kepler-452d was assigned to the planet because it was the third planet found in the Kepler-452 system. The first object, which is the star itself, is Kepler-452. The first planet discovered will be named Kepler-452b, the second planet Kepler-452c, third planet Kepler-452d and so on.

 

[mfb]

The name Kepler-452d was assigned to the planet because it was the third planet found in the Kepler-452 system. The first object, which is the star itself, is Kepler-452. The first planet discovered will be named Kepler-452b, the second planet Kepler-452c, third planet Kepler-452d and so on.

The planet is b, not d, as there is only one planet found so far.

The name Kepler-452 for the star system does not have a deeper meaning. The star did not have a name before, Kepler found something interesting that makes a name useful, and it is the 452th system that got a name by the Kepler scientists.

 

[Monsterboy]

We still had a lot of oxygen in the atmosphere, which is very reactive and doesn't stay around for long unless nonequilibrium reactions produce it. In addition, the atmosphere has methane and various other chemicals that do not live long in an oxygen-rich atmosphere. Sure, we did not emit radio waves back then, but the atmosphere has been unusual for a very long time.

Is it possible to find the atmospheric composition of Kepler 452b by spectral analysis or something , with current technology ?

 

[Monsterboy]

it is the 452th system that got a name by the Kepler scientists.

You mean 452nd solar system ?

 

[philton]

I'd like to bet that 452-b is not the only planet of the planetary system, considering the scale of the 452 system. Anybody follows?

 

[Borg]

You mean 452nd solar system ?

Here's the Wiki article on naming conventions for Kepler objects of interest (KOIs). It goes into a little detail on where the names come from and how they are assigned.

 

[|Glitch|]

http://www.nasa.gov/keplerbriefing0723

As I type this, NASA is announcing discovery of a new planet Kepler 452b that is
- small and (probably) rocky like Earth
- orbits a G2 star
- is in the star's habitable zone
This is the first candidate that meets all three criteria. (Most Earth-twins so far discovered are around tiny red dwarfs, and orbit in a matter of days) It has a 385 day long year, almost exactly the same as Earth.

Kepler 452b is a slightly older sibling of Earth - it has lived in its habitable zone for 6 billion years. It's a little bigger, surface gravity is about 2x Earth, but it probably has a thick atmosphere as well as volcanism.

One implication of this discovery is that these are surely common. We only detect 1 in 50 planets because of alignment issues, so detection of one suggests another 50 out there we can't see with current equipment.

The one imperfection in this otherwise ideal Earth-sister is that it is more than 1300 light years away.

There is apparently some question as to whether Kepler-452b meets your first criteria.

Most 1.6 Earth-radius Planets are Not Rocky - Leslie A. Rogers 2015 ApJ 801 41. doi:10.1088/0004-637X/801/1/41 (arXiv free reprint)

Furthermore, based upon Weiss & Marcy (2014) the density of Kepler-452b should be 7.956 (+1.123, -0.976) g/cm³, giving the exoplanet a gravity of 4.237 (+0.598, -0.520), or 41.554 m/s².

 

[|Glitch|]

Other articles put the star at 1400 ly.

http://www.npr.org/sections/thetwo-...ope-introduces-earth-to-a-very-distant-cousin

The planet is about 1.6 times the size of earth. It would be interesting to know the mass.

http://www.nasa.gov/keplerbriefing0723
Technical paper - http://www.nasa.gov/sites/default/files/atoms/files/ms-r1b.pdf

Based upon Weiss & Marcy (2014) the mass can be estimated based upon the planet's radius.

Exoplanets with a radius in the range of 1.5 ≤ R_P/R_⊕ < 4 have an estimated mass of M_P/M_⊕ = 2.69(R_P/R_⊕)^0.93. Which would put Kepler-452b's estimated mass at 4.237 (+0.598, -0.520) M_⊕.

 

[DaveC426913]

There is apparently some question as to whether Kepler-452b meets your first criteria.

Yep. That's why I said probably. Scientists are saying 'a better than even chance it's rocky'.

 

[mfb]

Is it possible to find the atmospheric composition of Kepler 452b by spectral analysis or something , with current technology ?

I would be surprised, the planet is far away, small and next to a relatively bright star. On the other hand, I'm surprised by science frequently...
E-ELT is under construction, spectroscopy of exoplanet atmospheres is one of the main science goals.

 

[|Glitch|]

I would be surprised, the planet is far away, small and next to a relatively bright star. On the other hand, I'm surprised by science frequently...
E-ELT is under construction, spectroscopy of exoplanet atmospheres is one of the main science goals.

Kepler-452b has one advantage going for it - the exoplanet was discovered using the transit method. Which should make the spectroscopy of Kepler-452b much more likely. Exoplanet atmospheres would be extremely difficult to discern if they did not transit in front of their parent star. We would have to wait until the James Webb Space Telescope came on-line in late 2018.

 

[DaveC426913]

Kepler-452b has one advantage going for it - the exoplanet was discovered using the transit method.

True. Though that makes me wonder why they don't already know whether its rocky or gaseous. Surely the light curve would be markedly different for each.

 

[mfb]

True. Though that makes me wonder why they don't already know whether its rocky or gaseous. Surely the light curve would be markedly different for each.

Why?
The orbital speed is about 30 km/s, an atmosphere of ~50 km (with relevant density) would influence the light curve by less than a percent (1% of a 0.01%-effect!), and only alter the shape for about 2 seconds each. There is no way to see such a small and short effect with Kepler.

 

[Bandersnatch]

True. Though that makes me wonder why they don't already know whether its rocky or gaseous. Surely the light curve would be markedly different for each.

Head to:
http://www.planethunters.org/
where you can help classify light curves collected by the Kepler mission. The follow up observations are somewhat more detailed, and their data can be seen in the discovery papers listed on that site.
It should help appreciate what kind of data constitutes a transit and how much can you read out of it.

Here's an example for Kepler-289 d:

 

[DaveC426913]

Head to:
http://www.planethunters.org/
where you can help classify light curves collected by the Kepler mission. The follow up observations are somewhat more detailed, and their data can be seen in the discovery papers listed on that site.
It should help appreciate what kind of data constitutes a transit and how much can you read out of it.

Yeah, I've done a fair bit of planet hunting there.

 

[LeDragonian]

They might be broadcasting their own version of Star-Trek!

Maybe they have a less annoying Cpt. T. Kirk.

 

[Mad scientist]

Is there any similar telescope planned to replace it eventually?

The James Webb Space Telescope is due to be launched in 2018:

http://jwst.nasa.gov/about.html

 

[rootone]

Yes I knew of the JWST, but this seems to be more of a replacement for Hubble (with extended infrared sensitivity).
I'm not sure if it could be used for the same type of planet-finding work which Kepler is doing.

 

[mfb]

TESS is basically an improved Kepler telescope.

It can reveal interesting candidates for observations with JWST which has a much broader science mission (JWST cannot keep observing the same stars for years).

PLATO could be even better, but certainly later.

See also the "Exoplanet search projects" navigation bar at the end of the article for more missions.

 

[Mad scientist]

Yes I knew of the JWST, but this seems to be more of a replacement for Hubble (with extended infrared sensitivity).
I'm not sure if it could be used for the same type of planet-finding work which Kepler is doing.

One of its main objectives is to study the atmospheres of exoplanets and search for the building blocks of life.

 

[Mad scientist]

The ESAis also planning the PLATO observatory to discover and characterize rocky extrasolar planets:

https://en.wikipedia.org/wiki/PLATO_( spacecraft )

 

[Arctura]

A tragedy this planet is so far away. At this distance it's very difficult to analyze the planets properties and all we can do are assumptions about the surface and interior. There may yet be types of planets we know nothing about and hence we cannot say for sure if this planet is earth-like at all. But every discovery is a step towards new knowledge and so I am very glad we kno finally about a potential earth-like planet around a sun-like star. The other information on the website are very interesting. If one boldly assumes there evolved intelligent life on this planet, the civilization could be very likely ahead of us or already lost to extinction. Well, listening won't hurt anyone...

 

[Mad scientist]

If one boldly assumes there evolved intelligent life on this planet, the civilization could be very likely ahead of us or already lost to extinction. Well, listening won't hurt anyone...

A civilization could also be less advanced than us too. The planet may be older than Earth but live could have evolved later than it did here.

 

[2milehi]

Maybe they have a less annoying Cpt. T. Kirk.

Or less whiny members on their physics forums.