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Galaxy clusters in SkySafari

I raised this some time ago but are there any plans (in SkySafari 7 perhaps) to add Galaxy clusters as an object type such as the Abell ones to the SkySafari database, and fix the errors with which galaxies are associated with which clusters in Sky Safari 6?

 

Owen

 

 

6 comments

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    Bill Tschumy

    Owen,

    We don't have any immediate plans to add galaxy clusters as a distinct object type.  However, it is not an unreasonable suggestion.

    Have you told us about the errors for which galaxies are part of which clusters?  We can certainly fix those if we know about them.

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    Owen

    Hi Bill

      if you do a search on Abell 1367 you get a lot (well 6) of galaxies listed that are in Coma whereas Abell 1367 is in Leo and they are in reality part of the Abell 1656 cluster. All the galaxies in the Abell 1367 group are  NGC 38** whereas those in Abell 1656 are NGC 48**. And yes I have told you about this before :-)

     

    In my case they all appear near the top of the search list.

     

    This is with 6.4.03

     

    Owen

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    Bill Tschumy

    Thanks for the additional info.  I don't have a recollection of being told about this but I'm not disputing that you did.  We get a lot of emails and postings.

    I will try to get this fixed in our next database rebuild.

     

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    Bill Tschumy

    Owen,

    I looked into these errors.  We get our cluster designations from the PGC catalog.  I see that these Coma galaxies are marked as part of both Abell 1657 and Abell 1367.  So it appears the error is in the original PGC galaxy catalog.

    It is not clear how we should handle this.  In general we take the catalogs as "truth".  We do not try to patch them up in any way.  So I wouldn't say this is a SkySafari error, but an error in the source data.

     

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    Owen

    well I guess as nobody else has noticed most of your users are probably not advanced enough to care..

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    Tom Polakis

    I'll add a second to Owen's feature request for plotting Abell Galaxy Clusters to the types of objects.  There are still a few features that the basic (and unsupported) charting program offers, so I still use it on occasion.  The screen grab below shows how it displays Abell 2092, labeled as "AGC 2092" at the left edge of the large circle.  Data for Abell galaxy clusters includes number of galaxies, size, and magnitude of the 10th brightest galaxy.

    Tom

     

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