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Repo Man

June 27th, 2006

Everything takes longer than you think it’s going to take.

I thought it would be a relatively straightforward task to collect and assemble all of the published radial velocity data sets together in a uniform format. Turns out (as is often the case) that I was overly optimistic. It’s been a major effort to get an authoritative radial velocity catalog into shape. Eugenio, however, has been extremely persistent and methodical, and the job is now essentially done. Datasets for 155 stars accompanied by published planets are now available on (1) the downloadable console, (2) the web-based console, and (3) on the systemic back-end. Many of these data sets are now available in ASCII format for the first time; Eugenio made extensive use of the Dexter applet to extract data from papers in which the radial velocities have been hitherto published only as plotted points.

As far as systems with published planets that are not on the console go, we’re definitely scraping the bottom of the barrel. This morning, Eugenio sent me an update on where he’s at with the last dregs. Basically, there are a dozen planet-bearing stars that still need to be added to the console. In most of these cases, we either can’t find any listing of data, or the data is available only in the form of a phased plot that can’t be disentangled:

0. HD114762: the two references I was able to find have (or appear to have) no uncertainties since the “planet” is likely a brown dwarf, I’ll still skip this one for now.

1. HD41004: hierarchical quad system: A(K star)-2.5 M_J/B(M star)-BD. Swiss give table of velocities for both A and B but no uncertainties.

2. Tau Bootes: This still looks like a hopeless cause.

3. GL86: phased velocities only.

4. HD11964: missing data?

5. HD122430: missing data?

6. HD196885: missing data?

7. HD34445: missing data?

8. HD59686: Only announced at American Astronomical Society Meeting; Still listed as Mitchell et al. 2004, ApJ, submitted.

9. HD73256: phased velocities only (do not confuse with HD 73526).

10. HD89307: missing data?

11. Tres-1: Phased velocities only.

Without a doubt, there are some easy as-yet unannounced and as-yet unpublished planets ripe for the picking off of the console menu. Two months ago, I wrote a series of posts showing that 51 Peg almost certainly has a second Saturn-mass planet in a habitable orbit. This planet was uncovered after only a few minutes of work on the console. This afternoon, Eugenio and I looked at four or five data-sets (basically at random) and found a nice planet candidate that we’re planning to write up in one of this week’s posts.

There are more than 6 billion people on Earth, and only a handful of them have discovered a planet. Here’s your chance.

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  1. Eugenio
    June 27th, 2006 at 15:11 | #1

    Hi all,

    I just made sure that all three components,
    the downloadable console, the web-based console,
    and the backend, had been updated. I’ll keep on
    looking for more to add, and a few data sets need to be polished.


  2. andy
    June 27th, 2006 at 15:29 | #2

    The new systems don’t come up in the downloadable console (though it is possible to access them using the other option). In addition, it doesn’t look like the offset sliders have enough range to handle Gamma Cephei…

  3. Eugenio
    June 27th, 2006 at 18:25 | #3

    Hi Andy,

    Thanks for the input. I believe I have fixed the
    downloadable console. I went through the process
    (on my linux machine) of downloading the zipped file, unzipping it, going into the systemic directory, and running “java -jar systemic.jar”.
    I was able to see all 176 “systems.” Please
    let us know if you still have difficulties.

    Some of our users may have noticed that a few systems in our list actually consist of brown
    dwarfs orbitting stars and stars with stellar
    companions. Particularly for these types of
    systems, the offset sliders may not have enough
    range. Gamma Cephei is the system with the worst
    case of this problem since offsets of around 2km/s are needed. This is a stellar binary system with a planet. The orbit for the binary must be fitted to be able to detect the planet, but this requires
    getting the offsets right first. We’re working on
    trying to properly handle these types of situations.


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