7 ms·

Go to http://exoplanet.eu/diagrams/ http://exoplanet.eu/diagrams/ and select "Semi-major axis" for the X axis (this is the appropriate analog of "radius" for an

Go to http://exoplanet.eu/diagrams/ http://exoplanet.eu/diagrams/ and select "Semi-major axis" for the X axis (this is the appropriate analog of "radius" for an ellipse) and "Planetary Mass" for the Y Axis. Note that the bottom right corner is empty because we can not yet detect stuff there. All of the solar systems planets would be in that corner. The Fulton gap is the lower density region at 0.1 to 0.2 jupiter masses.

scott_s 7y ago
For those following along at home: I had difficulty seeing it when the y-axis is on a log scale, because the gap between 0.1 and 0.2 Mjup is so small. I turned off log scale on the y-axis, then zoomed in so that the gap between 0.1 and 0.2 Mjup was actually discernible, and there I could see it. There's a lot of points that look to be basically on 0, which I assume are the planets below 0.1 Mjup. But for all points that don't look to be basically 0, there's an invisible asymptote they don't cross; there is not a smooth transition of points between basically 0 and clearly above 0.
- ummonk 7y ago
  Weird, I immediately saw it in the log-log graph. Like a vertical cut through the chart.
Balgair 7y ago
Here is an imgur link of the plots, as far as I could follow along: https://imgur.com/a/6TauNoU https://imgur.com/a/6TauNoU I'm not really seeing anything in the non-log scaled y-axis data. But the log scales of both data do seem to show three clear 'islands' of planetary sizes. EDIT: These' islands' in the data correspond to 3 planetary types (kindaaaa): Big and heavy super-gas-giants, small and lighter rocky planets, and heavy and smaller-ish gas giants. It's interesting to see there is a gap between the gas giant sizes and that it's not continious, despite them all being the same-ish mass.
- fwip 7y ago
  https://imgur.com/a/CLxSFIq https://imgur.com/a/CLxSFIq this is the 'gap' between .1MJup and .2 MJup - you can see it passes neatly between the islands you've observed.
  - Retric 7y ago
    Odd to call that a gap as it’s filled with planets. At best it’s a lower density area.
    - petschge 7y ago
      If you check the histogram plot at exoplanet.eu (also at https://imagebin.ca/v/4hRAHBxEtEbv https://imagebin.ca/v/4hRAHBxEtEbv for your convenience) you see that the density is quite a bit lower. And "Fulton gap" is simply a better name than "Fulton's possibly lower density mass range".
      - Retric 7y ago
        It does look like a bimodal distribution though it’s really 3 separate groupings smooshed into two peaks. However, gap generally reserved for lower valleys ie band gap etc. So, while shorter the term is simply misleading.
        petschge 7y ago
        You can get rid of the gas giant in your analysis by excluding everything further out than 0.2 AU. The distribution then separates more clearly into to peaks with a gap in between. But that is something I can not get in a minute or two in the online plotting tool. Also you should be aware that astronomy and astrophysics has quite different conventions for naming things than say condensed matter. Part of the reason is that historically they were a separate science from physics. Part of the reason is that most of the knowledge is gained from (passive) observations, not actively controlled experiments.
petschge 7y ago
Since a lot of people seem to have problems with that plot I have uploaded an annotated version to https://imagebin.ca/v/4hQOkAKo27fq https://imagebin.ca/v/4hQOkAKo27fq . The black dots are data and are correct. The colorful annotations are by me and might be wrong as I am a plasma physicist, not a planetary scientist. And unfortunately I can not get the dots for the solar system in there using the plot interface of exoplanet.eu. But they would be in the bottom right triangle.
- Havoc 7y ago
  Thanks for this

scott_s 7y ago

For those following along at home: I had difficulty seeing it when the y-axis is on a log scale, because the gap between 0.1 and 0.2 Mjup is so small. I turned off log scale on the y-axis, then zoomed in so that the gap between 0.1 and 0.2 Mjup was actually discernible, and there I could see it. There's a lot of points that look to be basically on 0, which I assume are the planets below 0.1 Mjup. But for all points that don't look to be basically 0, there's an invisible asymptote they don't cross; there is not a smooth transition of points between basically 0 and clearly above 0.

ummonk 7y ago
Weird, I immediately saw it in the log-log graph. Like a vertical cut through the chart.

Balgair 7y ago

Here is an imgur link of the plots, as far as I could follow along: https://imgur.com/a/6TauNoU https://imgur.com/a/6TauNoU I'm not really seeing anything in the non-log scaled y-axis data. But the log scales of both data do seem to show three clear 'islands' of planetary sizes. EDIT: These' islands' in the data correspond to 3 planetary types (kindaaaa): Big and heavy super-gas-giants, small and lighter rocky planets, and heavy and smaller-ish gas giants. It's interesting to see there is a gap between the gas giant sizes and that it's not continious, despite them all being the same-ish mass.

fwip 7y ago
https://imgur.com/a/CLxSFIq https://imgur.com/a/CLxSFIq this is the 'gap' between .1MJup and .2 MJup - you can see it passes neatly between the islands you've observed.
- Retric 7y ago
  Odd to call that a gap as it’s filled with planets. At best it’s a lower density area.
  - petschge 7y ago
    If you check the histogram plot at exoplanet.eu (also at https://imagebin.ca/v/4hRAHBxEtEbv https://imagebin.ca/v/4hRAHBxEtEbv for your convenience) you see that the density is quite a bit lower. And "Fulton gap" is simply a better name than "Fulton's possibly lower density mass range".
    - Retric 7y ago
      It does look like a bimodal distribution though it’s really 3 separate groupings smooshed into two peaks. However, gap generally reserved for lower valleys ie band gap etc. So, while shorter the term is simply misleading.
      - petschge 7y ago
        You can get rid of the gas giant in your analysis by excluding everything further out than 0.2 AU. The distribution then separates more clearly into to peaks with a gap in between. But that is something I can not get in a minute or two in the online plotting tool. Also you should be aware that astronomy and astrophysics has quite different conventions for naming things than say condensed matter. Part of the reason is that historically they were a separate science from physics. Part of the reason is that most of the knowledge is gained from (passive) observations, not actively controlled experiments.

petschge 7y ago

Since a lot of people seem to have problems with that plot I have uploaded an annotated version to https://imagebin.ca/v/4hQOkAKo27fq https://imagebin.ca/v/4hQOkAKo27fq . The black dots are data and are correct. The colorful annotations are by me and might be wrong as I am a plasma physicist, not a planetary scientist. And unfortunately I can not get the dots for the solar system in there using the plot interface of exoplanet.eu. But they would be in the bottom right triangle.

Havoc 7y ago
Thanks for this