Exoplanet Stats

It might be nice to have a thread on the latest exoplanet data presentations.

Here is the current results I've found. [This, admttedly, is as much about having fun in VBA coding as in seeing where we are with exoplanets.]

There are about 136 exoplanets in the habitable zone. 3 of these have a mass < 1.9 Earth masses, but > 0.5 Earth masses.

Notice the HZ range is bumped by 3.9%. This is a result of today's article here, where an 8% luminosity change would allow a planet with less water to not freeze, etc. The 3.9% is the distance for 8%, in accord with the inverse square law.

Perhaps the only way to settle the science here concerning habitable zone exoplanets or habitable exoplanets, will be to do what I watched on Lost in Space recently. Someone must go there :)
The JWST may improve things. There are more and better observing telescopes planned including Plato, which will monitor over 200k stars. Better spectroscopy will help determine exoplanetary atmosphere compositions, which may produce some strong life signs.

I agree that at some point we must go there, though with a probe initially.

We live in a special time since for centuries there have only been dreams regarding whether or not other planets beyond the Sun might exist. The exoponential growth rate of their numbers is really something to see.

All this data, as expected, produces things unexpected. For instance, why are there fewer planets around M-class stars? I would assume these smaller stars would have smaller disks, thus fewer and smaller planets, perhaps. But these planets orbit close to their "red" host and would be easier to observed -- the "low hanging fruit". Are they too dim or something?
The exoplanet count (per The Extrasolar Planet Encyclopaedia — Catalog Listing (exoplanet.eu) is today at 4,969, just 31 away from 5000!

We should celebarate the 5000 mark, perhaps. :)

The stats, otherwise, haven't changed. It stands, as above, at 136 exoplanets in the HZ using a 3.9% bump to both the inner and outer HZ limits. Three of these exoplanets have Earth masses between 0.5 and 1.9.

[The above is from my little Excel program but using HZ equations.]
Today's count has grown by 9 since yesterday (4978 exoplanets). [The HZ number is unchanged at 136 with the 3.9% bump to the limits.]

So, in the next few days, perhaps up to a week, we should cross the 5000 milestone!
Here's an update. The program is a bit more sophisticated.

The first column are the new inputs allowed for Users.

There are 14 Exoplanets in the HZ that meet the User's limits for radii -- from 1 to 3x the radius of the Earth.

[Radii are used in lieu of mass due to the much greater number of known radii compared to exoplanetary masses.]
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The program now lists all those HZ exoplanets that are within the User's radii limits. [Again 1 to 3x that of Earth's radius for this example.]

Here they are:

The red color for a cell simply means it can't be observed from the User's location (per their latitude).

The other colored cells represent three separate methods of calculation to test whether or not they are in the HZ.

The "Std. Method" is the calculation with known stellar magnitude, distance, and type to find luminosity.
The "Temp Method" is found knowing the temperature and radius of the star, thus giving us the luminosity.
The percentages stated in these cells represent the planets placement related to the HZ itself. Thus a value of 0% to 100% puts it in the HZ, but, a value of, say, -50%, means that the exoplanet is located short of the HZ by half the total width of the HZ .

The "Equil. Meth." is the method that calculates the equilibrium temperature of the exoplanet. The cyan cell color means it is in the HZ.

Only the exoplanets that are found to be in the HZ are highlighted in bright green in the first two methods. Thus, those that aren't bright green are in disagreement with the other one that does show it to be in the HZ.

The same is true for the blue cells, should any of them have not blue highlight.

The blank cells are due to the fact that the database does not contain all the required values to do all three calculations. If the data is unavailable to do the calculation, the cell is left blank.
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"Science begets knowledge, opinion ignorance.

OK by me :) :) :) :) :) :) :) :) See #1 :) :) :) :) :) :) :) :) :) :) :) :) :) :) :)

Cat :)

For any who do not understand, Helio has done an enormous amount of work on exoplanets, and also has expressed very positive views on the colour of the Sun!
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Oct 23, 2019
Cat- I haven't checked out the spreadsheet if that's what you're asking. I saw the screenshots of the vba excel spreadsheet and they look very professional. It seems you are also saying that the 5000 exoplanet was found? If so, yes of course it should be named after Helio. I don't see why not. I've always thought Kepler 442b was the higher candidate for life on another planet but after looking at Helios data now I think it's kepler 452b. If it weren't for Helios data I would not have otherwise been aware of Kepler 452b. So I'm really happy about that.
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I'm a little surprised that we haven't quite broke the 5k barrier. The Exoplanet.eu catalog has actually dropped two from the list and is stuck at 4,980, so we are very close.

Here is a graph (thumbnail, so click on it) showing the rate that planets have been discovered, all beginning in 1995. This is the lates feature in the VBA Exoplanet program (free to any that ask and have Excel to run it).

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That seems wise, but it shouldn't take long, should it?

Cat :)
Right, it shouldn't.

But I did, finally, find where one can download the NASA exoplanet data and also put it the .csv format, which Excel can use.

But, the NASA file is over 57 MB! It took several minutes to download. I selected all the main data for all exoplanets but excluded the data for the margins of errors, thus reducing the file size to 57 MB. This NASA file includes data for 287 columns, though the error columns are included in this total (all blank as requested by me).

In comparison, the exoplanet.eu site data is only 2.3 MB, even with the error columns and the data for them. This site has on 98 columns.

I doubt there is any substantive difference between the two for amateurs like me.

Perhaps someone with more time on their hands and analyze the difference between them. I have a lot on my plate for the next few months, but I hope to get to this someday.

The NASA page to go to in order to obtain the download is: Nasa Exoplanet Download page. [see "Download Table" in the header.]


"Science begets knowledge, opinion ignorance.
Helio, sadly I never got involved with Excel (though I do have the program on my laptop). I do, however, remember my Finance Director showing me pages of printouts to justify what we should have done if we'd had the data to input at the time. Excuses, excuses! That's what I paid him to do? ;)
Helio, sadly I never got involved with Excel (though I do have the program on my laptop). I do, however, remember my Finance Director showing me pages of printouts to justify what we should have done if we'd had the data to input at the time. Excuses, excuses! That's what I paid him to do? ;)
I would bet you would have fun with Excel if you had to make, say, a listing of your books, or something.

But you wouldn't want to pay anyone to type the NASA listing as it would take well over a year of 8-hr days to do so if one averaged more than about 7 sec. per cell. :)
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I used Excel to catalog all my books. Below is a general idea how I did it.

The code causes Excel to look at the table data and find the match, then it places it for you in the next column, reducing the typing efforts.

Each column can be sorted and still maintain the connection to the other columns.

Once you get accustomed to Excel, you may discover you want to do more, and a lot more it can do, as you've seen in this thread. :)

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"Science begets knowledge, opinion ignorance.
Helio, I am approaching 83, and I would rather spend my time reading than cataloguing. Although some cataloguing is necessary. I have told you about my subdural haematoma and my memory retention. I actually keep by records (SHAME) on Word. To me, it is just a list.

But I do envy your excellence on Excel.

Cat :)
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