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Planetary Nebula surface brightness

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#1 AKHalea

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Posted 13 November 2019 - 02:45 PM

Recently, I got interested in imaging Planetary nebulae. With my limited gear (4" refractor), only a handful of the typical PNs are easily imaged. There was a list of brightest PNs that was published here on CN a few years ago (see this thread from 2010). However, that list did not have many of the bigger (but fainter) PNs like Sh2-216 and HFG1.

 

I think the old DSO Browser (now Telescopius) has a function to sort out PNs, but last I checked, it was still missing the 2nd largest (but fainter) PN, Sh2-216. In my research, I found an interesting link that catalogs many of the PN emission spectra, but its nomenclature for the names is missing. Any idea what these “names” (like A-2, A-8, A-12) etc are equivalent to more conventional names (like Abell 6 Abell 21, CTB1, HFG1 etc)? 

 

So, does anyone have an updated list that shows PNs by size and visual brightness? If there is a list that contains some ideas of surface brightness, that will be even better. Thanks ..... Anil

 



#2 bortle2

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Posted 14 November 2019 - 08:25 AM

So, does anyone have an updated list that shows PNs by size and visual brightness? If there is a list that contains some ideas of surface brightness, that will be even better. Thanks ..... Anil

At sharplesscatalog.com, there is a Links and Downloads page, at the bottom of which there is downloadable Sharpless Catalog: a ZIP file with PDF and XLSX files inside; both contain (among other things) PN sizes and brightness info, although brightness is only given as faint / midrange / bright.

 

The list is not sorted by size and/or brightness (or rather is sorted by IDs), but you can easily do it yourself: load .xlsx file into Excel/LibreOffice/OpenOffice (Calc), select all rows except very first (the header), and then go to Data --> Sort... When dialog box appears, select Column E or Column F as Sort Key 1 (the former if you want to sort by size, the latter if you want to sort by brightness).

 

BTW, thanks for the links, appreciated.



#3 astroian

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Posted 14 November 2019 - 10:08 AM

That’s a great link, thanks for providing it.

There was an explosion of interest in PNe by professional astronomers during the 60s. As a result there are many small catalogues of these objects, some with only a few entries.

The names will be related to specific catalogues, e.g. K1-10 will be for Kohoutek 1-10. They may or may not have other names that are more familiar, although many will have a PK or PNG catalogue entry. I would recommend the HASH database which you can access for free. Google ”HASH planetary nebula” should bring you up a link.

Cheers,
Ian
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#4 bortle2

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Posted 14 November 2019 - 11:16 AM

I would recommend the HASH database which you can access for free. Google ”HASH planetary nebula” should bring you up a link.

Thanks for the hint! Found it, registered (it's required), and had a look...

 

It's comprehensive, no doubt: 3,560 objects. The database is downloadable, but no size/brightness info in it, unfortunately, so not that useful for target selection.

 

If however one needs information on a particular object, it's super-handy: full spectral information (easy to use charts), images (including .fits), size in arcsecs... I wonder why they didn't include size in database/downloadable data, it'd be so useful. Also, I could find only eight objects from Sh-2 catalog; the rest must be overlapping with other catalog(s), which would complicate search a bit.

 

Anyway, thanks again.


Edited by bortle2, 14 November 2019 - 11:21 AM.

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#5 AKHalea

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Posted 14 November 2019 - 12:45 PM

Ian : Thanks for the HASH database idea. 

 

Bortle2 : Thanks for providing the Sharpless object DB and the link to the HASH DB link. The DB does have size information. You just have to click on "show columns" at the bottom and tick the size and type information there. Happy hunting ..... Anil 


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#6 chrysalis

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Posted 14 November 2019 - 12:48 PM

Best comprehensive one that I like to use:

 

http://www.virtualcolony.com/sac/


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#7 bortle2

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Posted 14 November 2019 - 01:06 PM

The DB does have size information. You just have to click on "show columns" at the bottom and tick the size and type information there.

WOW, indeed; thank you!

 

Somehow, I have a feeling that it's Christmas around here already...


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#8 bortle2

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Posted 14 November 2019 - 02:19 PM

Best comprehensive one that I like to use:

 

http://www.virtualcolony.com/sac/

Mark, thank you so much.

 

You just helped me find the... well, ultimate database with that link. The page you linked says:

 

The first 15 searches use the Saguaro Astronomy Club database version 8.1, dated March 22, 2010.

 

I followed that link, searched saguaroastro.org, and found this treasure trove: http://www.saguaroas.../sac-downloads/

 

On that page, the database used by virtualcolony.com is available as a 4 megabyte XLS file withing the following ZIP file: http://www.saguaroas...epSky_ver81.zip

 

Complete with full documentation. In fact, what virtualcolony.com shows as "Database Documentation" text is contents of the Sacdoc.txt file from the above archive.

 

An absolute wealth of information, so easily sortable and searchable: magnitude, surface brightness, angular sizes, even position angle (something I'd love to use for initial positioning of the rotating focuser), you name it...

 

The virtualcolony.com supports 17 types of searches:

  • Galaxies
  • Galaxy Clusters
  • Open clusters
  • Globular clusters
  • Bright and dark nebulae
  • Planetary Nebulae  <-- AKHalea, please take notice!
  • Messier objects
  • Caldwell objects
  • Best of the NGC
  • Herschel 400 objects
  • Herschel 2500 objects
  • Asterisms, single and multiple stars with NGC designations
  • LMC and SMC objects
  • Supernova Remnants
  • All objects within a constellation

All of that is in the SAC_DeepSky_ver81_Excel.xls file within SAC_DeepSky_ver81.zip, easily selectable by type.


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#9 AKHalea

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Posted 14 November 2019 - 03:17 PM

Mark : Thanks for the pointer to SAC's exhaustive list! Will look it over. 

 

Bortle2 : Thanks for the XLS spreadsheet download. That is a very informative worksheet ..... Anil



#10 astroian

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Posted 14 November 2019 - 04:11 PM

Mark: thanks for the link to this resource.

 

Bortle2: thanks for the link to the download, really useful.

 

Cheers,

Ian



#11 astroian

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Posted 15 November 2019 - 03:13 AM

Some further information on the HASH database can be found here: https://arxiv.org/abs/1612.00167

You can download it using the PDF link in the top right corner.

Cheers,
Ian
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#12 AKHalea

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Posted 15 November 2019 - 11:31 AM

Ian : Thanks for the link. Always helps to have as much info as we can get in the planning stage. Cheers ..... Anil



#13 AKHalea

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Posted 16 November 2019 - 09:55 AM

For anyone following this thread : I found an old CN thread that lists all the large PNs targets for NB imaging with a low focal length telescope (like a 4" refractor). It is a great resource. 

 

It was written by one of the mods here, Goofi, who recently passed away. So we are indebted to this very fine gentleman for putting together a complete list with the sizes of these PNs and added notes to help us with imaging. Cheers ..... Anil


Edited by AKHalea, 16 November 2019 - 09:58 AM.


#14 akulapanam

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Posted 16 November 2019 - 02:09 PM

Most complete list should be on Simbad. http://simbad.u-strasbg.fr/simbad/


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