Pixinsight astrometric annotation catalogs

That’s an interesting subject, Scott. And yes, would be great if we could share that info here. I am using the following non-default catalogue:

Arp catalogue without duplicates (338 objects)
The default PI/Vizier catalogue tags an Arp object that consists of multiple objects as many times as there are objects, all with the same Arp-number. The attached catalogue has just one entry for each Arp object.

Arp_NoDuplicates.csv

Did you say you have a Hickson catalogue? Does it label each Hickson object as one, or does it tag the a, b, c etc objects? Would you mind sharing here?

In theory, VizieR can readily produce any of these catalogs in nearly ready to go format, but most of the VizieR catalog requests go to a site in France, and something seems to be geo-blocking at the network layer hindering its use a bit. There are mirrors but not all of them (including Harvard’s and Russia’s) are up or accessible.

Anyway, I’ve been finding the original papers where these catalogs were first published and just using any means necessary to munge them into PixInsight annotation format. I did a few yesterday of various star clusters. I started working on HMSTG, which is much bigger than those. Meanwhile I keep trying ways to gain access to the data at VizieR without resorting to VPN.

Re: VizieR at Harvard, there’s a message from a year ago (May 23, 2025) on the main French portal that: “The Harvard mirror hosting CDS services (Vizier, Simbad, Sesame) is currently down. The websites will be unavailable for a few days, please use the Strasbourg sites during the downtime. down.”

Caldwell completed today.

I realize there may be some copyright and permissions issues with some of this stuff. Im documenting sources and data conversions for each catalog as I go.

I’ll have a git repo setup soon and I’ll see if there’s also a way I can release these as a bundle via the Pixinsight repository system.

Paul Puntin · Jun 5, 2026 at 10:43 AM

Hi Scott, great idea and something I’ve been looking for as well, but I didn’t know how to create the catalogues. Now I do. I found a Hyperleda file created by Ben Kolt in this Cloudynights post. It’s very big as you can imagine.

Also, it might be worth contacting Juan at Pixinsight as he has included catalogues (LDN, LBN) generated by other users into the Pixinsight AnnotateImage script in the past.

https://www.cloudynights.com/forums/topic/702361-what-galaxy-catalog-to-use-for-annotations-in-pi/

Hi Paul, thanks, I appreciate it! There’s a trick that can be done in AnnotateImage to dynamically produce a custom catalog specific to the astrometric coordinates of an image. It’s a little green arrow to the right of the custom catalog file path field. But this function called “CatalogDownloader” has been broken recently and I’m not sure if it’s fixed in the latest version (the release notes in AnnotateImage claim so, but I’m getting an error and may need to update Pixinsight core). Anyway, that may be a helpful utility for very specific situations and long focal length fields of view.

I’m going to try to finish two or three more on my plate now and then I will present on the Pixinsight forum ASAP.

Scott Stirling · Jun 3, 2026 at 01:04 AM

I am working on it — using an image of the Prawn and False Comet area of southern Scorpius that has a good mix including:

• Collinder (Cr)

• RCW

• Sandqvist & Landroos

• Trumpler

📷 Prawn_annotated-v2a.jpgThe Hickson catalog, formatted by Fred Vanner and corrected by him and other users, is attached.

Hickson-galaxies-v2-from-Fred-Vanner_PixInsight_forum-04-22-2023.txt

📷 The Prawn Nebula, Northern Jewel Box, False Comet and Dark Tower

https://app.astrobin.com/i/sqoasg/

Updated …

• Caldwell ( C )

• Cederblad (Ced)

• Hartley et al southern dark clouds (DCld)

  Working on a few more (SFO, Gum, MBM) and release process.

Paul Puntin · Jun 6, 2026 at 02:14 PM

I’ve just created a King catalogue of open clusters, if you want to include it.

King.txt

That’s a good one, Paul. I will add it!

Demonstrating work in progress to show how much is "going on" from a southern celestial hemisphere annotation perspective. I disabled the redundancy filter in AnnotateImage to show all the catalog items for demonstration purposes. Shown here are items from a PixInsight custom catalog project including: Dutra and Bica Dark Clouds ([DB2002b]), Caldwell (C), Cederblad (Ced), Collinder (Cr), FeSt 1 and FeSt 2, Green (SNR), Gum, Hartley et al (DCld)), RCW, Sandqvist and Lindroos (SL) and Trumpler. In addition, enabled here, are built-in PK, NGC-IC and Barnard, which show a few items in overlap. Lynds' LBN and LDN catalogs may have more overlap here with these catalogs so I disabled LBN and LDN here.

📷 The Prawn Nebula, Northern Jewel Box, False Comet and Dark Tower

https://app.astrobin.com/i/sqoasg/

Paul, that’s great, and looks good. While you’re at it, if you have time and interest please try this one:

Kharchenko-et-al-Clusters-Master-Catalog-2013-for-PixInsight.csv

This catalog is a revised master catalog of all the clusters including the catalogs of Collinder, King, Melotte, Muzzio, Stock, Trumpler and more. Some clusters have been eliminated in their revisions, though, as they decided that some previously identified clusters were asterisms or were actually divided into multiple clusters (e.g., Trumpler 24 in Scorpius was divided into multiple separate clusters).

I read about the catalog and pulled the necessary fields from VizieR and organized, munged the data as necessary for PixInsight and tested it. Here are three examples with clusters I used for testing. The Milky Way shot has a few other annotations enabled but the blue circles are all the clusters from the Kharchenko catalog, which officially uses the designations MWSC or [KPS2013], but I set the catalog to display the clusters’ more familiar common names from the catalog notes.

I have about two dozen catalogs converted and tested for PixInsight and it has taught me several things.

First off, did you know that you can display additional fields in annotations from file-based catalog data? Check out the built-in Messier catalog with AnnotateImage and you can see that the labels drop down has options to display magnitude, diameter, “common name” (which is stored in the Messier.csv) and other things and multiple placement options for the labels. I am planning to make this possible with custom and Vizier-based catalogs, but currently those types do not support this feature.

Another thing I found the hard way more than once is that if you add a Custom catalog layer in AnnotateImage and you forget to browse to the path for its file before clicking “OK,” then all previously configured custom catalogs are removed from your preferences the next time you open the script.

Another thing is that using local catalog files (as PixInsight does for Messier, NGC-IC and NamedStars csv files locally) seems better than hitting VizieR for any common catalog with less than a few thousand items. The network latency to VizieR becomes noticeable and sometimes it hangs completely and PixInsight hangs on VizieR timing out. We could easily store all of Sharpless-2, Lynds LDN and LBN, Barnard and VdB and a couple dozen more well-known and modestly sized catalogs locally and the annotations would run much faster. Currently every one of those catalogs, if enabled, requires a network round trip to France (because Harvard’s VizieR portal has been down for over a year, what’s up with that?). Granted, it only queries for the data relevant to your image (for enabled catalogs), and it caches results locally for future reference, supposedly, but it seems VizieR always get called even I am annotating the same image over and over and nothing has changed.

I think that we could do something like a “deploy” directory that AnnotateImage could check for new catalog files and a json or xml metadata file, run a validation on any new catalog files, and enable users to add/edit/remove custom catalogs with all the same features available to file based catalogs such as Messier.

I think that customizing a turbo version of AnnotateImage is going to be the best way to release and maintain these catalogs and support their usage collaboratively. I think it is high time for PixInsight and Astrobin to have better annotation support out of the box for the southern hemisphere and some newer astronomical catalogs that astrophotographers find and will continue to find useful and interesting.

I need some sleep but I’m looking to release this as PixInsight update repository ASAP, like a day or two or three.

📷 DoubleCluster_in_Perseus-annotated-v2.jpg📷 RCW-38_Image136_annotated.jpg📷 MergeMosaic_Preview01_annotated-clusters.jpgP.S. notes on the MWSC catalog provenance and multiyear project: it has a part III containing 139 newly identified clusters in the northern hemisphere, which I have pulled down but not yet incorporated to that catalog for PixInsight. The current version attached to this message has all 3,006 clusters from part I and part II, covering northern and southern hemispheres.

Author: Kharchenko, N.V., Piskunov, A.E., Schilbach, E., Roser, S. and Scholz, R.D.
Title: Global Survey of Star Clusters in the Milky Way II
VizieR Catalog ID: J/A+A/543/A156
Date: October, 2013
Publisher: Astronomy & Astrophysics, Volume 558, id.A53, 8 pp.

Sources: https://www.aanda.org/articles/aa/pdf/2013/10/aa22302-13.pdf, https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/558/A53, https://doi.org/10.1051/0004-6361/201322302

P.S. currently the annotation layers are mapped to files rather than say a json query or even regex filter. A local file based query /filter system might be nice for consolidating catalog files. But as yet in order to enable flexibility it is helpful to have catalogs isolated at the file layer. So I’m keeping the King contribution along with separate Melotte and Trumpler catalogs for the layering flexibility.

More info on the bug with AnnotationImage settings and custom catalog layers getting deleted issue!

The issue is related to validation of the custom catalog path which occurs only after clicking “OK” on the AnnotateImage main dialog, and only if the added Custom layer is enabled to be visible (which is checked by default when adding), which is too late to edit it. You get a dialog warning about missing enabled custom catalog layer files before it runs the annotation, but no opportunity to fix it before it runs.

I tested different scenarios to narrow it down to this:

• Enabled Custom catalog layers must have a catalog file path set or else they fail validation later on annotation script execution, and that results in the first invalid Custom catalog layer AND all layers lower in priority to be omitted from the settings.

• Disabled Custom catalog layers without catalog file path configured cause no issues. Only when they are enabled are they validated and have potential to wipe out other settings, even the default layers.

• Enabling a Custom catalog layer without a configured catalog file path will cause it and every layer below it in priority to be removed from user settings for AnnotateImage. If it is at the top of the layers priority list it will cause all the other layers to be removed.

• The workaround is to hit the reset button in the lower left and start back with preconfigured defaults.

• The fix is less clear yet because the catalogs and layers are tied into a more general persistence system in PixInsight which is in control of the validation cycle. I’m investigating options.

I have a prototype working with externally configured custom catalogs in a JSON config. More soon.

Scott

Awesome, Paul, that looks great. BFS catalog for the HII regions will be interesting to see applied too. And Dutra and Bica’s Dust Clouds. These are newer catalogs that update and in some cases fix issues with earlier catalogs. For example, Sharpless 2 is way off by several arcminutes in the galactic core region due to some historical date and coordinate calculation errors. BFS (Blitz, Fich and Stark I think), are good, and added 63 new HII nebula too. So I’m enabling these layers by default in my AnnotateImageExt script. Maybe AnnotateImagePlus, idk, need a better name or Ext is it!

Those object ls you noticed — great observation and connects with my feeling when going deeper into these images and their contents too — they both are classified as other than clusters:

IC1795 is an HII region:

https://simbad.cds.unistra.fr/simbad/sim-basic?Ident=IC1795&submit=SIMBAD+search

And NGC896 is listed as an interstellar medium, ISM, object.

P.S. all 3 of these catalogs I mentioned above index objects across north and south hemispheres, so for example, all the Gum and RCW and Sharpless objects are sorted and validated and normalized in BFS. Several Sharpless 2 and RCW objects turned out not to be HII or sometimes not to be coordinates for anything anyone can find, stuff like that across all these “catalogs of catalogs.”