3 ms·

I would have liked to hear about how they are now accounting for the inherent bias of our detection process to find large, close-to-star planets, because those

I would have liked to hear about how they are now accounting for the inherent bias of our detection process to find large, close-to-star planets, because those are the ones that produce the best signals. I remember that that used to be a big issue in drawing any statistical conclusions about expolanet data. Has there just finally been enough data collected that we can model our own bias?

cwmma 8y ago
The article says that half of the nearby stars have these large close-in planets, which would suggest that even if there are biases in the detection mechanism it's still at least as common a type of system as ours.
empath75 8y ago
Yeah exactly this. We’re not finding any solar systems like our own because we _can’t_. It’s possible that the majority of stars that we don’t see planets around look exactly like ours and we wouldn’t know.
jerf 8y ago
I have read in other articles that, yes, this very obvious issue has been taken into account and yes, there is still a surplus of solar systems not like ours even so. Hard to link one, though, since there's a lot of noise from articles that don't mention this.
adminonymous 8y ago
Along the lines of this "detection bias," I've long wondered if there's another bias: the orbital angle of the exoplanets with respect to the plane of ours. If the detection is based on transit across the star of the system, what if we're looking at the axis of the planetary system, and not its equator? All systems similarly oriented toward our instruments would come up as a false negative, no? (I'm not an astronomer, please correct my jargon).
- wlesieutre 8y ago
  You're correct that most of our detection is by transits in front of stars and will only see planets with orbital planes aligned toward us. However, it's super cool to note that we've actually directly imaged expoplanets orbiting around their stars in other planes: https://en.wikipedia.org/wiki/List_of_directly_imaged_exoplanets https://en.wikipedia.org/wiki/List_of_directly_imaged_exopla... Another possibility is detecting planets by the wobble that they introduce in the star's position. I'm not well read on the subject, but I wonder if Gaia's position measurements via parallax are accurate enough for this. EDIT: A bunch more information from Wikipedia on detection methods https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanet... The space-based observatory Gaia, launched in 2013, is expected to find thousands of planets via astrometry, but prior to the launch of Gaia, no planet detected by astrometry had been confirmed.

cwmma 8y ago

The article says that half of the nearby stars have these large close-in planets, which would suggest that even if there are biases in the detection mechanism it's still at least as common a type of system as ours.

empath75 8y ago

Yeah exactly this. We’re not finding any solar systems like our own because we _can’t_. It’s possible that the majority of stars that we don’t see planets around look exactly like ours and we wouldn’t know.

jerf 8y ago

I have read in other articles that, yes, this very obvious issue has been taken into account and yes, there is still a surplus of solar systems not like ours even so. Hard to link one, though, since there's a lot of noise from articles that don't mention this.

adminonymous 8y ago

Along the lines of this "detection bias," I've long wondered if there's another bias: the orbital angle of the exoplanets with respect to the plane of ours. If the detection is based on transit across the star of the system, what if we're looking at the axis of the planetary system, and not its equator? All systems similarly oriented toward our instruments would come up as a false negative, no? (I'm not an astronomer, please correct my jargon).

wlesieutre 8y ago
You're correct that most of our detection is by transits in front of stars and will only see planets with orbital planes aligned toward us. However, it's super cool to note that we've actually directly imaged expoplanets orbiting around their stars in other planes: https://en.wikipedia.org/wiki/List_of_directly_imaged_exoplanets https://en.wikipedia.org/wiki/List_of_directly_imaged_exopla... Another possibility is detecting planets by the wobble that they introduce in the star's position. I'm not well read on the subject, but I wonder if Gaia's position measurements via parallax are accurate enough for this. EDIT: A bunch more information from Wikipedia on detection methods https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanets https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanet... The space-based observatory Gaia, launched in 2013, is expected to find thousands of planets via astrometry, but prior to the launch of Gaia, no planet detected by astrometry had been confirmed.