# Tight grouping of exoplanets 295RA 45dec

• I
Gold Member
does anyone have any information on why the vast majority of exoplanets are located in one spot? any papers on the topic?

the following link does not graph RA vs DEC but instead does something about planet size, if you wish to use it please select RA for the x-axis and DEC for the y-axis, both linear or you can use any other data set it should show the same thing

https://exoplanetarchive.ipac.caltech.edu/cgi-bin/IcePlotter/nph-icePlotInit?mode=demo&set=confirmed

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Bandersnatch
Large planets are easiest to detect.

mathman
If you are talking about size, it is simply a fact that larger exoplanets are easier to detect.

Gold Member
Large planets are easiest to detect.

most of the planets in that direction are a little smaller than average

Gold Member
If you are talking about size, it is simply a fact that larger exoplanets are easier to detect.

most of the planets in that direction are a little smaller than average

Bandersnatch
most of the planets in that direction are a little smaller than average
What direction? Smaller than average what? Please, make yourself clear.

Drakkith
Staff Emeritus
most of the planets in that direction are a little smaller than average

If you're referring to the big cluster of planets in the upper right of the graph, they are all approximately the size of Jupiter, likely putting them WELL over the average planetary mass and radius. Big planets, like big stars, should be greatly outnumbered by their smaller and less massive peers (just like we see here in our own solar system). We just can't find these smaller planets as easily.

smartalek86
Gold Member
If you're referring to the big cluster of planets in the upper right of the graph, they are all approximately the size of Jupiter, likely putting them WELL over the average planetary mass and radius. Big planets, like big stars, should be greatly outnumbered by their smaller and less massive peers (just like we see here in our own solar system). We just can't find these smaller planets as easily.

lets not be earth-sized-centric here ;) the tight grouping is mostly average-sized if not slightly smaller than the rest of the exoplanet data: graph planet size vs RA and DEC and you will see most of the grouping at RA295ish and DEC45ish fall in the middle and definitely not on the large size, however, i'm not sure why this topic is continuing to veer off OP and talk about planet size?

as Drakkith confirmed "the big cluster of planets in the upper right of the graph", lets get back to the OP which is why is there a "the big cluster of planets in the upper right of the graph"? more precisely RA295ish and DEC45ish [i do loath non-galactic coordinates] has there been any studies on this? i did a quick google search but was unsuccessful

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Gold Member
What direction? Smaller than average what? Please, make yourself clear.

i'm having bad memories of undergrad when a geology TA took off points on my lab report for not specifying the subducting pacific plate was on earth

edit: now that i know people are responding to the incorrectly used graph instead of the OP, this comment may not apply my apologies

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Staff Emeritus
i'm not sure why this topic is continuing to veer off OP and talk about planet size?

Because the default histogram the OP pointed us to includes size. To get RA vs DEC you need to take additional steps. (Steps the OP neglecvted to mention) Also, the excess is at more like RA 280 than 195.

nearc
Gold Member
Because the default histogram the OP pointed us to includes size. To get RA vs DEC you need to take additional steps. (Steps the OP neglecvted to mention) Also, the excess is at more like RA 280 than 195.

thanks for pointing out the typo, meant to say 295RA, fixed my replies but can not change original title [edit: yes, fixed original OP title] should we close this and reopen a new thread? also the link defaults to something other than i copied, but that is just one external link an only needed if people need some sort of confirmation

Drakkith
Staff Emeritus
lets get back to the OP which is why is there a "the big cluster of planets in the upper right of the graph"? has there been any studies on this? i did a quick google search but was unsuccessful

I wasn't aware that we'd gotten off-topic. I thought we were talking about why the cluster of planets appeared in that particular spot on the mass vs radius plot, to which the answer is that larger, more massive planets are much easier to detect than smaller, less massive planets.

If you are asking why most of those planets are around 290 RA and 45 DEC, then it's probably because that's where the Kepler spacecraft was looking for the duration of its mission. The center of its FOV falls almost exactly at 290 RA and +45 DEC.

nearc
Gold Member
I wasn't aware that we'd gotten off-topic. I thought we were talking about why the cluster of planets appeared in that particular spot on the mass vs radius plot, to which the answer is that larger, more massive planets are much easier to detect than smaller, less massive planets.

If you are asking why most of those planets are around 290 RA and 45 DEC, then it's probably because that's where the Kepler spacecraft was looking for the duration of its mission. The center of its FOV falls almost exactly at 290 RA and +45 DEC.

thanks a bunch, that makes sense, however, the following figure suggests its center is around 37 DEC is that correct?

https://en.wikipedia.org/wiki/Kepler_(spacecraft)#/media/File:Kepler_FOV_hiRes.jpg

Gold Member
Nope. Notice that the DEC lines are curved.

wow, i'm not paying attention, thanks again