[Stellar Mapping] CTIOPI dataset added, Stellar Mapping page reorganised!

I have now added the CTIOPI (Cerro Tololo Interamerican Observatory Parallax Investigation) dataset to my Stellar Mapping page! CTIOPI is another dataset from the RECONS group, aimed at locating red, white, and brown dwarfs that are within 25pc of Sol – it adds 164 stars that are mostly contained within 300 ly of Sol. However, it only covers (roughly) the southern sky as viewed from Earth, so only about half of the volume around Sol contains stars from this dataset – that said, the distribution of CTIOPI stars could be used as a guideline for adding fictional stars in the rest of the volume.

CTIOPI dataset, looking corewards.

I have also edited the DENSE dataset to remove all the stars that were duplicated in CTIOPI and HIPPARCOS datasets – the most accurate data has been retained (the original DENSE dataset is no longer available here, though I may make it available again in a later blog update). The CTIOPI dataset has also been edited somewhat to remove duplicates (none of the CTIOPI stars have HIP numbers though, though it does include one star – HIP 3856 – that is missing from the Hipparcos dataset). All CTIOPI entries within 22.7 lightyears have also been removed to avoid overlap with RECONS.

This means that there should now be no duplicated stars at all if the RECONS, DENSE, CTIOPI and HIPPARCOS datasets are used together, so the combined dataset is now about as accurate as it can be. Full details of these edits can be found in the “CTIOPI-DENSE merging details” section in the Astrosynthesis.txt and Galactic.txt files contained in the new RECONS-DENSE-CTIOPI.zip file available from Section 2 of the Stellar Mapping page.

I’ve also updated and reorganised the Stellar Mapping page to (hopefully) make it easier to decide which datasets to use. If you have already downloaded the DENSE dataset then you should download it again to make sure you have the latest version!

5 Responses to “[Stellar Mapping] CTIOPI dataset added, Stellar Mapping page reorganised!”

  • Hope you used the actual papers for the white dwarfs instead of the DENSE website 🙂

    In case you’re interested, here’s a list of parallaxes and spectral data along with academic citations for L and T brown dwarfs:


  • Oo, thanks for that! Are those all trigonometric parallaxes?

    And yes, I did refer to the papers – I actually noticed a few errors on the DENSE website 🙂

  • They’re spectroscopic or photometric parallaxes. After I entered the closer ones, I discovered Preliminary Trigonemetric Parallaxes from the USNO here:


    Hmmm. That looks like it might not work. Lemme find the subdirectory on Vizier for it…

    Well darn, it’s not in Vizier. The paper can be downloaded here:


    That’ll teach me to get in a hurry 🙂

  • After re-checking all the brown dwarfs within 10 parsecs, I can report that the first list does indeed contain trigonometric parallaxes where available. All the ones I checked, except the first one of course, matched either the USNO list or the following paper:


    Looks like I needlessly panicked myself 🙂

    I’ll go hunt up the reference that I don’t have.

    Looks like this list is closest to a RECONS list for brown dwarfs that you’re going to find.

    • Yeah, thanks for finding that! I did imported the list you posted in to AS, and I think there was one or two BDs that weren’t in the RECONS list (which was interesting – I wonder why those were missed by RECONS). There are BDs that are further out that are already in the CTIOPI database and have different parallaxes, so I’m going to go with the CTIOPI values for those instead. I’ll see if I can tidy up the BD dataset and remove the duplicates and post it up on the Stellar Mapping page at some point.

      On the plus side I did find that there’s a conveniently placed BD that can connect Xi Bootis to the previously isolated clump that contained Arcturus and Eta Bootis (I’ve been looking for a link there for a while, I need that for the 2300AD project), so that’s really useful! 🙂

      Thanks again!

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