Exoplanet Stats

[Helio]

You're welcome. I find Excel VBA coding more fun than assembling jig-saw puzzles.

So, here's some colorful fodder to consider.

The attempt is to package key features of a system to allow a quick glance at what's in each system. The table only is tabulating the three exoplanet systems. I'm hopefully someone here will have suggestions that will improve this, thus allow less coding time for the other multi-systems.

The pattern following the system name includes:
1) A number that gives the size of the planet per the table below. The font is also bumped up for the larger planets to make exo size more visual. [This whole project, for that matter, has been quite and exo-size. ]
2) The cell color that reveals the exos proximity to its star. For instance, red is hot and green shows it is in its HZ.

It sure demonstrates that these systems have mostly exos that are, well, toast! So, these will be the rocky planets, but the more massive ones could retain an atmosphere, albeit hot.

There are only two systems that have Earth-like exoplanets ("2") in their HZ.

[Exos in a system that had zero mass were deleted. Thus, for example, a 4-exo system with one of zero mass makes it a 3-exo system here. I'm unsure if I like doing this, so thoughts?]

tiny image hosting

 

[ImmortalMelvz]

Here is the current "summary".



The prior post shows actual planet names for all but the M-type stellar systems.

Thank you, M means we are going to Multiply to populate the habitable exoplanets!

 

[Helio]

Here is a 4-exo system table. I've added the star type, when given, and replaced the unknown mass exoplanets with "?", but the color does represent where it is located relative to its sister planets, as well as, the thermal zone (cell color).

 

[billslugg]

You get a big planet with many times Earth's gravity and lots of water and insolation, there are going to be some big storms.

 

[Unclear Engineer]

Not seeing much in the way of "2" to the right of "7" in that table, so not seeing much evidence for an Earth-like planet orbiting outside of a Jupiter-like planet.

But, almost everything we are discovering is "hot" at this point. So, maybe we just are not seeing the earth-like planets where there are "hot Jupiters"?

I am not thinking that this data can really help verify or falsify planet development modes until we are better at finding all of the planets at least as far out as the outer edge of the habitable zone.

 

[Helio]

Not seeing much in the way of "2" to the right of "7" in that table, so not seeing much evidence for an Earth-like planet orbiting outside of a Jupiter-like planet.

But, almost everything we are discovering is "hot" at this point. So, maybe we just are not seeing the earth-like planets where there are "hot Jupiters"?

I am not thinking that this data can really help verify or falsify planet development modes until we are better at finding all of the planets at least as far out as the outer edge of the habitable zone.

Yes. Obeservational bias has been a given from day one. Confirmation requires observations for three orbits, so more distant exos will necessarily be fewer in number for the hotter stars.
For a non-pinball formation model, smaller exos that orbit beyond a Jupiter or larger-sized exo would have formed farther out than the sweet spot just past the frost line. Thus, it could take several decades to see these at larger AU distances using the methods that require the three-orbit requirement for confirmation.

But better direct-type observations will come online at some point and these, I assume, will reveal a lot more, and will not require three orbits for confirmation.

 

[Unclear Engineer]

Considering the trouble we are currently having with finding or disproving our own system's "Planet 9", I think it is going to be hard to find much more distant exoplanets directly - even small ones at distances about 1 AU from stars similar to our Sun.

But, I was thinking that if we were finding small rocky planets in habitable zones but outside the orbits of "hot Jupiters", that would call into question the theories in the article in the other thread.

Since we don't seem to be finding that arrangement, I am not seeing any challenge to the theory from our observations, so far.

 

[Helio]

Considering the trouble we are currently having with finding or disproving our own system's "Planet 9", I think it is going to be hard to find much more distant exoplanets directly - even small ones at distances about 1 AU from stars similar to our Sun.

[I meant to comment on this a few days ago.]

There are about 200 directly imaged exoplanets, so only about 2-1/2% of all exoplanets confirmed.

It's one of those cool things in astronomy where something non-intuitive happens.

The drop in brightness of planets as they are farther away from us is dramatic. So much so that Jupiter, if bumped to about 10k AU, would be invisible to the HST at its 31 app. mag. limit. This is an inverse 4th power law (inv. sq. for light to an object and inv. square of light returning to the observer).

Yet, if my math is correct, a Jupiter at 1 AU distance from a sun-like star would be visible up to about 1000 light years. At 1 AU, I get that Jupiter would have an apparent mag. of -8.4 (if we are viewing from the Sun's position, or we see it from one AU distance from Earth but ignore the reduction due to the phase angle).

At 5,000 light years, the inverse sq. law (not a 4th power, hence the huge difference) would drop its brightness by ~ 5.5E15 times, or a magnitude decrease of 39. Reducing the 39 by -8.4 puts it at the limit of the HST. This ignores all the noise problems, so 5,000 lt. years is too optimistic. But this may be in range for the JWST.

[ checking my math would be advisable.]

Mean mag Jupiter​	-2.2
semi maj.:​	5.2
AU dist. inward:​	4.2
Brightness of 4th power law:​	311.2
App. mag. diff.:​	6.2
Jup. Revised app. mag.:​	-8.4
New dist., lyrs.:​	5000
1 lt yr =​	63,241
Dist. In AU:​	316,205,000
Dist. Ratio:​	7.53E+07
Inv. Sq. law:​	5.67E+15
Mag.:​	39.4
Net mag. diff.:​	30.9

 

[Helio]

BTW, I don't like all the red, so I've changed the colors so only the likely toasted exoplanets are red, followed by the less hellish planets having lighter tints.

 

[Helio]

So, here are the latest color upgrades on the multi-system exoplanets (legend to follow). See above for explanations. [As always, courtesy of Exoplanet.eu] [I set a mass limit of 25 Jupiters (8,000 Earth masses) in the following (less than the legend shows), whereas the catalog allows up to a little over 70 jupiters, unlike the NASA site, IIRC.]

free photo host

 

[Helio]

 

[Helio]

 

[Helio]

The key color, of course, is the bright green, which represents the HZ (Habitable Zone) where liquid water is expected to exist.

 

[Helio]

While I'm at it, here is the bigger, summary story: