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2019 Additions / Changes
Completed a page about cartoons by Daumier
related to the nonexistent comet of 1857.
Started a major partial update of the page for NGC 4050 - 4099
Completed a major partial update of the page for NGC 4100 - 4149
Added images and discussion for NGC 1052-DF2
and NGC 1052-DF4, the first galaxies known to have no dark matter.
Per a request, completed the entry for NGC 4144
Updated the images for NGC 6052
(= NGC 6064) to take advantage of an improved HST image of the colliding galaxies.
Due to a note letting me know about a minor error in my entry for NGC 3194 (= NGC 3155
), corrected the error, added a new image of NGC 3155, and changed its galaxy classification based on the far better image.
As part of a test of image availability, added PanSTARRS images of NGC 1000
Completed a major partial update of the page for NGC 2850 - 2899
Fixed a broken link involving The Oppositions of Mars
Completed entries for four galaxies shown in an HST image of PGC 44716
As part of an update for NGC 2850 - 2899, posted an image of Arp 275
Completed a major partial update of the page for NGC 2800 - 2849
2018 Additions / Changes
Due to a query about NGC 1573
, completely updated and finished that entry.
Completed a major partial update of the pages for NGC 2750 - 2799
Completed a major partial update of the page for NGC 2700 - 2749
Due to a query about IC 1101
, updated its entry (which is now complete).
Completed a major partial update of the pages for NGC 2650 - 2699
and PGC 25130
Completed a major partial update of the page for NGC 2600 - 2649
Completed a major partial update of the page for NGC 2550 - 2599
Completed a major partial update of the page for NGC 2500 - 2549
Completed a major partial update of the page for NGC 2450 - 2499
Completed listing P-K numbers for all NGC objects (but still have to take care of IC entries).
Due to a query about a mislabeled HST image, posted an entry (and images) for dwarf irregular galaxy PGC 51472
Continued posting P-K numbers (through NGC 3195), and added images for NGC 2867
Posting the P-K number for planetary nebula NGC 2452
, noticed that there were some far better images now available, so posted those as well.
Started posting Perek-Kohoutek planetary nebulae designations for NGC objects (reached NGC 2440).
late Sep - mid Oct:
Worked on a number of things but didn't finish any due to personal and family illnesses.
Posted an entry for and images of the Phoenix Dwarf Galaxy
Currently working on the page for NGC 4650 - 4699, but to take advantage of a just-released HST image of the Blue Planetary nebula, NGC 3918
, created a completed entry for that object.
Took advantage of an Adam Block image of NGC 5866
to update its entry.
Took advantage of a new HST image of NGC 6139
to update its entry.
Took advantage of a new image of NGC 6052
to update its entry.
Resumed work on this site; results to be posted as available.
Mar 21 - May 27:
For various reasons took an extended break from updating this site.
A colleague noticed that the recessional velocities of two galaxies had been considerably changed in the NED catalog since the last time I posted the entries for NGC 2406
and 2407, so corrected the presumably erroneous older values, and reposted the hopefully more nearly correct entries.
Took advantage of an HST press release to update the entry for IC 4710
Updated the entry for Francis Abbott
Thanks to an email pointing out an error in one of the references for my NGC/IC catalog (and as a result, a corresponding error in my own catalog), corrected, updated and completed the entry for NGC 2257
, a globular cluster in the Large Magellanic Cloud.
Added a new HST image of NGC 1559
, and slightly updated its entry to reflect that.
Did a substantial (though not total) update of The Local Group
(of galaxies), adding several images, updating captions, tags and some of the text. Lots more to do to bring it fully up to date (it was originally written well over ten years ago), but that's it for the current iteration.
Posted the image of NGC 7331
from today's HST press release.
Created a page for Non-Traditional Discovery Dates
(which see for an explanation of its purpose).
Added discussion and images of interacting galaxies PGC 1431761
Added PanSTARRS image for IC 58
Changed the discovery dates for IC 59
for reasons discussed in their entries; also added a PanSTARRS image for IC 60
Due to the availability of an HST image of NGC 6090
, completely updated the entry for that object.
Completed checking Corwin/Steinicke/discovery updates of NGC 6050 - 6099, added image of Arp 209
to the Arp Atlas page.
Completed checking Corwin/Steinicke/discovery updates of NGC 6000 - 6049, added all data for HCG 79.
As part of the (currently incomplete) update of NGC 6000 - 6049, added images and links (but not data) to the entry for Hickson Compact Group 79
, also known as NGC 6027
, or Seyfert's Sextet.
To take advantage of the HST press release of Jan 1, 2018, completely updated the three entries on the page for PGC 33000 - 33499
2017 Additions / Changes
Completed Corwin/Steinicke/discoverer updates for NGC 5950 - 5999. Also posted HST images of NGC 3147
. Also, over the last week or so have also added numerous references and links to previously listed entries to Historical Reference Papers for the NGC/IC Objects
Completed Corwin/Steinicke/discoverer updates for NGC 5900 - 5949.
Completed Corwin/Steinicke/discoverer updates for NGC 5850 - 5899.
Completed Corwin/Steinicke/discoverer updates for NGC 5800 - 5849.
Completed Corwin/Steinicke/discoverer updates for NGC 5750 - 5799.
Completed Corwin/Steinicke updates for NGC 5700 - 5749.
Completed Corwin/Steinicke updates for NGC 5650 - 5699.
Posted an HST image of the core of globular cluster M79
Completed Corwin/Steinicke updates for NGC 5600 - 5649.
Completed updated discussion of NGC 5256
Added multiple SDSS and HST images to entry for NGC 5256
. Also finished creating all (mostly placeholder) pages for open clusters OCL 1 - 1039
(which is all of them).
Added just-released wide-field image of region near NGC 6559
. (One more to add, ASAP)
Added a discussion and images of reflection and emission nebulae NGC 6559
Finished a post for PGC 53183
(as a result of an HST press release of Dec 4).
Created a preliminary page and template for open clusters: OCL 900 - 949
Completed Corwin/Steinicke entries/updates for NGC 5550 - 5599.
Completed Corwin/Steinicke entries/updates for NGC 5500 - 5549.
Updated a discussion and images of IC 2497
and Hanny's Voorwerp.
Translated Darquier's 1782 paper about observations of Bode's 1779 comet and his discovery of the Ring Nebula and added a link to his paper to the reference list
for NGC/IC objects.
Reversed the order of discovery for M57
, per an article in the June issue of Sky & Telescope.
Completed Corwin/Steinicke entries/updates for NGC 5450 to 5499.
Completed Corwin/Steinicke entries/updates for NGC 5350 to 5449.
While checking Corwin & Steinicke's databases for NGC 5308 to 5349, added an image of NGC 5335
Nov 14 - 17:
While checking Corwin & Steinicke's databases for NGC 5150 to 5307, added an HST image of planetary nebula NGC 5307
, and added preliminary entries for the members of Hickson Compact Group 67
Added an HST image of NGC 4625
to its entry.
Checked Corwin's positions for NGC 4870 to 5149.
Checked Corwin's positions for NGC 4710 to 4869.
Nov 6 - 8:
Checked Corwin's positions for NGC 4250 to 4709.
Took advantage of an Apr 2017 HST image of NGC 4298
to update the entries for those galaxies.
Added an HST image of the central ring of M94
to its entry.
Took advantage of the HST Picture of the Week to update the entry for NGC 4993
Took advantage of the HST Picture of the Week to add an entry for PGC 17302
Posted an HST image of globular cluster NGC 7006
In response to a question, added the page What Is The Gravitational Constant, G?
. The page needs some fact-checking and editing, but is a reasonable introduction of the question, IS
the gravitational constant truly a "constant"?
Posted fully updated entry for NGC 7009
, based on ESO news release of that date.
Took advantage of the HST Picture of the Week to add an entry for PGC 31961
. Also updated the entry for NGC 7009
, in preparation for a further update on Sep 27.
Took advantage of the HST Picture of the Week to update and complete the entry for NGC 5398
, and began a long-overdue update of the page for NGC 5350 - 5399; but due to pressing real-world concerns, have yet to finish the page.
Took advantage of the HST Picture of the Week to update and complete the entry for NGC 5559
. Also updated thumbnails and links for Arp 286
To take advantage of a new HST image of NGC 5765
, completely updated and finished its entry.
Since it was referenced in the discussion of IC 511
, did a complete update for IC 520
, and as a result of a search for images of IC 520, also updated IC 5201
Aug 21 - 22:
While taking care of the changes noted in the previous update, I discovered that all four objects observed by Lewis Swift on Sep 1, 1888 had the same 10 minute of time error in their recorded positions. This required updating IC 511
, PGC 24397
and NGC 2646
. Also did a thorough update of the entries for the pair of interacting galaxies known as NGC 5730
and NGC 5731
Aug 20 - 21:
Thanks to a suggestion by Steve Gottlieb, Harold Corwin has shown that three objects observed by Lewis Swift on Sep 1, 1888 had a 10 minute of time error in their recorded right ascensions, so after nearly 140 years of being "lost" or (even worse) misidentified, they have now been correctly identified. Complete updates for all three objects (IC 895
) and for the objects they were previously misidentified as have now been posted to reflect those corrections.
Am sick, so (sniffle) will miss seeing the total eclipse on Aug 21, and make little if any progress on this website for a few days. However, I have taken advantage of a beautifully processed HST image of IC 3568
to completely update its entry (though, despite the note for Aug 11, only on one of the 50+ entry pages at the moment).
Since most catalogs of NGC/IC objects have individual pages for each object, decided to start creating such pages for all the objects in my catalog. I will also retain the 50+ entry per page format, as it provides a more convenient way to browse through a number of objects at a time, and will only create individual pages as I have the time. But a few individual pages have been created as an example of the new (additional) format, such as for NGC 1
, NGC 2
Took advantage of an HST image of NGC 4656
to update its entry.
Finished a complete review of NGC 1 - 49
, checking/confirming and updating everything (text and images), so that it is now as complete and up to date as currently possible, save for a few minor problems which will hopefully be resolved within a few days. In the meantime I will be starting a similar review and update of NGC 50 - 99. However, progress will be slow through the end of August due to minor medical issues and a hopefully successful effort to view the Aug 21 total solar eclipse.
Still need to finish update of IC 300 - 349
, but did finish an iteration of IC 350 - 399
Completed basic update of NGC 350 - 399
; and within a couple of items of finishing similar update of IC 300 - 349
Posted HST images of NGC 248
and PGC 31693
to the entries of the same name.
Posted an HST image and discussion of PGC 16643
Posted an HST image and discussion of PGC 52112
Working on considerable update of IC 300 - 349
Jun 16 - 20:
Completed current iteration of NGC 300 - 349
. Also added a discussion
of where the material on my NGC/IC Catalog pages comes from (but still need to update the discussion of image sources and copyrights).
Jun 12 - 15:
Completed current iteration of IC 250 - 299
Completed current iteration of NGC 250 - 299
Completed current iteration of IC 200 - 249
. Also revised formatting for erindalepublishing.com as a test of ways to improve tablet viewing of cseligman.com. If the changes prove useful and effective, will start revising the formatting for cseligman.com in bits and pieces over the next few months. If not, will test other approaches beforehand.
Because of the August solar eclipse, posted an updated discussion of safe ways to view the eclipse
Completed most historical updating for NGC 200 - 249
Completed current updating of IC 150 - 199
May 29 - 31:
Changed the navigation banner
and the NGC/IC/PGC link tables
to better accommodate mobile devices (refreshing such devices in landscape mode seems to do a better job of clearing cached files), and started a major overhaul of IC 150 - 199
as a template for a clearer explanation of physical information for galaxies in the NGC/IC/PGC catalogues.
Finished checking historical and Dreyer entries for NGC 150 - 199
Finished adding about a hundred images of NGC 7300 - 7349
Have now added several hundred entries and more than a hundred online reference links to Historical Reference Papers for the NGC/IC Objects
Finished checking historical and Dreyer entries for NGC 100 - 149
and IC 100 - 149
Finished checking historical and Dreyer entries for NGC 50 - 99
(some serious questions remain, but basic work done) and IC 50 - 99
Posted an entry and images of PGC 18516
, also known as IRAS 06076-2139, due to the publication of an HST image of the pair of interacting galaxies. (More to be added to the discussion later today or tomorrow.)
Completed entries (and URLs) for all of Guillaume Bigourdan
's (currently known) papers shown on the Historical Reference Papers
page. (Some reference details differ from Steinicke's list; data on my reference page are taken directly from Bigourdan's files.)
Updated Dreyer NGC entries for NGC 7800 - 7840
and NGC 1 - 49
, and updated Dreyer IC entries (and added some images) for IC 1 - 49
Completed Dreyer NGC entries for NGC 7750 - 7799
Started a page listing the hundreds of references
I use for my NGC/IC catalog, and links to online versions of the references.
Completed Dreyer NGC entries for NGC 7700 - 7749
Completed Dreyer NGC entries for NGC 7650 - 7699
Completed Dreyer NGC entries for NGC 7600 - 7649
Completed Dreyer NGC entries for NGC 7550 - 7599
Completed Dreyer NGC entries for NGC 7450 - 7499
and NGC 7500 - 7549
Did considerable historical research and unearthed photos of A. N. Skinner
and Mathieu-Prosper Henry
(also sent to Wolfgang Steinicke, who posted them on his website).
Completed Dreyer NGC entries for NGC 7350 - 7399
and NGC 7400 - 7449
Completed Dreyer NGC entries for NGC 7300 - 7349
Completed Dreyer NGC entries for NGC 7250 - 7299
Completed Dreyer NGC entries for NGC 7200 - 7249
Completed Dreyer NGC entries for NGC 7100 - 7149
and NGC 7150 - 7199
; also added a better image of NGC 7144
Completed Dreyer NGC entries for NGC 7050 - 7099
; also added a better image of NGC 7079
Completed Dreyer NGC entries for NGC 6950 - 6999
and NGC 7000 - 7049
Completed Dreyer NGC entries for NGC 6850 - 6899
. Also updated the NGC/IC entries for all ten nebulae discovered by Auguste Voigt
in 1865, but not published until 1987. Also checked Dreyer NGC entries and discovery data for NGC 6900 - 6949
, which is what led to the consideration of Voigt's efforts.
Completed Dreyer NGC entries for NGC 6800 - 6849
Corrected or explained inconsistent discovery dates for numerous objects observed by William Herschel prior to their "official" discovery dates, e.g. NGC 6802
Completed Dreyer NGC entries for NGC 6750 - 6799
(though the remaining items from Mar 22 still need to be dealt with).
Completed Dreyer NGC entries for NGC 6700 - 6749
and corrected a longstanding error in the identification of NGC 6748
, which turns out to be a misrecorded observation of NGC 6751
Completed Dreyer NGC entries for NGC 6650 - 6699
Cleared up the situation with NGC 6607
(though the remaining items from Mar 22 still need to be dealt with), and completed Dreyer NGC entries for NGC 6600 - 6649
More or less completed a discussion of the confusing situation involving NGC 6607
, NGC 6608
, NGC 6609
and PGC 61556
Completed adding Dreyer NGC entries for NGC 6500 - 6549
and NGC 6550 - 6599
Completed adding Dreyer NGC entries for NGC 6400 - 6449
and NGC 6450 - 6499
Completed adding Dreyer NGC entries for NGC 6300 - 6349
and checking NGC 6350 - 6399
Completed Dreyer NGC entries for NGC 6200 - 6249
and NGC 6250 - 6299
Completed Dreyer NGC entries for NGC 6150 - 6199
Completed Dreyer NGC entries for NGC 6100 - 6149
Completed Dreyer NGC entries for NGC 6050 - 6099
Completed Dreyer NGC entries for NGC 5950 - 5999
and NGC 6000 - 6049
Completed Dreyer NGC entries for NGC 5900 - 5949
Completed Dreyer NGC entries for NGC 5800 - 5849
and NGC 5850 - 5899
. Also corrected a misidentification of a plate flaw as a (nonexistent) galaxy (see NGC 5861
and the following entry).
Completed Dreyer NGC entries for NGC 5700 - 5749
and NGC 5750 - 5799
Completed Dreyer NGC entries for NGC 5650 - 5699
Completed Dreyer NGC entries for NGC 5550 - 5599
and started same for NGC 5650 - 5699
Updated/corrected discovery information for M25
(= IC 4725
). Also updated the entries for NGC 7210
to reflect the relatively recent discovery that the former was a prior observation of the latter.
Updated NGC 1450
with PanSTARRS images, to supplement the lower quality DSS images. Also corrected errors for NGC 990
(incorrect/incomplete discovery dates) and 1180
Finished updating the entries for NGC 1265
, IC 312
and PGC 12287
Gottlieb and Corwin have just shown that NGC 1265
PGC 12287, but IC 312
. I am too sick to completely update the entries involved, but have posted preliminary corrections that make the situation reasonably clear.
Fixed an error in the discovery information for IC 3927
(thanks to Gary Kronk).
Finished my third novel (An Unsuitable Suit
), and will now resume work on this website.
2016 Additions / Changes
Took advantage of a recent HST image of spiral galaxy NGC 4388
to update its entry.
Took advantage of a recent HST image of irregular galaxy IC 3583
to update its entry.
Posted images and a discussion of variable Seyfert galaxy Markarian 1018
Posted just-released HST image of spiral galaxy NGC 3274
Fixed an error in the entry for NGC 1641
, which is usually listed as part of the Large Magellanic Cloud, but is actually part of our own galaxy.
Resumed updating of NGC 1550 - 1599
. Also finished the first draft of my third novel, so should start making more progress on this site in the not too distant future.
Posted just-released HST image of dwarf irregular galaxy PGC 43869
(= "NGC 4789A").
Posted new HST image of NGC 1222
, and discovered I hadn't finished updating NGC 1200 - 1249
, so rectified that mistake.
Nov 1 - 5:
Continued updating NGC 1550 - 1599
to current "minimum" standard.
Oct 29 - 31:
Completed current iteration of NGC 1500 - 1549
and started updating NGC 1550 - 1599
Added a new HST image of the Crab Nebula
(M1); also continued updating NGC 1500 - 1549
Oct 25 - 26:
Returned to updating NGC 1500 - 1549
. Also decided to create a new template for PGC objects, to reduce the number of objects on a single page, and used a previously empty page (PGC 121000 - 121499
) to try it out, creating four additional pages (e.g., PGC 121100 - 121199
) to reduce the number of objects per page from 500 to 100. It will take quite a while to do the same for all the PGC pages (especially since this is a low-priority matter), and the link table will remain as-is, only linking to the first page out of a group of five pages, to keep its size more manageable.
Posted a recent HST image and comment for globular cluster NGC 362
Completed current iteration of IC 1550 - 1599
Updated entries for NGC 5562
due to a query about the latter galaxy's discovery. Also resumed work on IC 1550 - 1599
Altered the entries for NGC 457
to reflect Wolfgang Steinicke's recent discovery that William Herschel observed these objects (though not as "clusters") during his early studies of double stars (that is, prior to his efforts to discover nebulae and clusters of stars).
Returned to updating IC 1550 - 1599
Took advantage of the release of a HST image of NGC 299
to replace the 'raw' Hubble Legacy Archive image of the open cluster.
Updated the home page
and scrollable fiction banner at the top of all other pages to reflect the release of the five short stories in "Short Shorts" as individual Kindle "singles".
Oct 11 - 13:
Due to the (incorrect) suggestion that IC 1560
might be NGC 164
, started updating IC 1550 - 1599
Added a new HST image of NGC 278
Oct 7 - 10:
Added previously incomplete discovery information for NGC 100 - 149
and started the same for NGC 150 - 199
. Also started updating some of the NGC/IC Discoverers
Updated discovery information for several Messier objects (see here
Oct 5 - 6:
Started updating NGC 1500 - 1549
Sep 28 - Oct 4:
Completed current iteration of NGC 1450 - 1499
Added a newly released HST image of NGC 24
to its entry; also continued to update NGC 1450 - 1499
Sep 24 - 25:
Started updating NGC 1450 - 1499
Sep 13 - 23:
Completed current updating of NGC 1400 - 1449
. (delayed by a death in the family)
Took advantage of a newly released HST image of PGC 83677
to post pictures and a discussion of that galaxy.
Sep 9 - 11:
Continued updating NGC 1400 - 1449
Aug 29 - Sep 8:
Finished updating NGC 1350 - 1399
, started NGC 1400 - 1449
Aug 25 - 27:
Finised basic updating NGC 1300 - 1349
; started updating NGC 1350 - 1399
Aug 23 - 24:
Finished basic updating of NGC 5250 - 5299
To take advantage of a new HST image of NGC 5264
, added Steinicke and partial Dreyer historical data to NGC 5250 - 5299
Aug 16 - 21:
Continued updating NGC 1300 - 1349
Took advantage of just-posted HST images of Pisces A
and Pisces B
to do entries for those galaxies.
Aug 14 - 15:
Started updating NGC 1300 - 1349
Aug 9 - 13:
Completed current iteration of NGC 1250 - 1299
Took advantage of a just-posted HST image of NGC 2337
to do a detailed entry for that galaxy.
Aug 4 - 8:
Continued work on NGC 1250 - 1299
Posted images of NGC 4833
and continued work on NGC 1250 - 1299
Jul 31 - Aug 2:
Continued work on current iteration of NGC 1250 - 1299
Completed current iteration of NGC 1200 - 1249
, started on NGC 1250 - 1299
Added an image of the Moon passing in front of the Earth during a solar eclipse to Pictures of the Moon
Changed the entries for NGC 832
and NGC 1226
to reflect the recent discovery that they are probably duplicate entries.
Jul 18 - 25:
Continued updating NGC 1200 - 1249
Posted an update to Browser Help
explaining how to reach the target of a broken link (caused by the target page either disappearing or its website being reorganized).
Jul 13 - 16:
Started updating NGC 1200 - 1249
. Also posted images and a discussion of the peculiar galaxy PGC 7090
. Also posted notes about Arp 310
, and a warning about occasional misidentifications of Arp 310 as NGC 1259
(it is actually IC 1259
Jul 9 - 13:
Considerably updated NGC 1150 - 1199
. Also posted images and a discussion of the Hubble Picture of the Week of PGC 56779
Jul 6 - 9:
Completed basic updating of NGC 1100 - 1149
. Also added a Warning About Load Time for Some Sky Atlas Pages
to the banner at the top of every page on this site.
Jul 2 - 5:
Posted positions and wide-field images for all Hickson Compact Groups
, and started altering NGC entries for HCG members to take advantage of that. Posted brief notes about a possible identification of the otherwise "lost or nonexistent" NGC 111
. Also posted a biography and images for Auguste Voigt
Jun 30 - Jul 1:
Started updating formatting for NGC 1150 - 1199; also updated data and images for Hickson Compact Groups
11, 12 and 21.
Jun 27 - 28:
Finished formatting/pix/tags through NGC 1099. Checked Corwin positions and added/checked original NGC entries through 1149. Started updating formatting for NGC 1100 - 1149.
Jun 16 - 19:
Completed NGC entries for NGC 1050 - 1099
, updated formatting/pix through NGC 1093.
Jun 13 - 15:
Updated formatting and many images for NGC 200 through 249.
Updated formatting and numerous images for NGC 127 through 149.
Added another image of the Hoba meteorite to the page about Meteorites
, and enlarged on the comments about the object. Also, due to a recent Hubblesite post about UGC 4879 (= PGC 26142
), posted images and a preliminary discussion of that galaxy.
Jun 4 - 5:
Updated formatting and numerous images for NGC 191 through 199, and NGC 124 through 126.
May 29 - Jun 1:
Updated Corwin positions through NGC 1099, added and/or verified original NGC entries, updated formatting and added many images through NGC 1052. Also updated formatting and images for NGC 150 - 190, as that task was overlooked while otherwise updating NGC 124 - 249 in March.
Updated Dreyer entries/etc through NGC 990.
Posted a discussion and images of the Vela Ring Galaxy
and its companion..
May 19 - 21:
Updated Dreyer entries/etc through NGC 970.
Posted a first draft of The Effect of Metals On Heat Flow Inside Stars
, and moved The Extremely Metal-Poor Galaxy AGC198691
to that page.
Updated Dreyer entries/etc through NGC 952; as a result, also modified the entry for NGC 940.
May 16 - 17:
Updated Corwin positions through NGC 999, Dreyer entries, pix etc through NGC 949.
Updated Dreyer entries, formatting and added/updated pix through NGC 899.
Posted a temporary entry for extremely "metal-poor" dwarf irregular galaxy AGC198691
May 10 - 14:
Updated Corwin positions through NGC 899, Dreyer entries, current formatting and new/updated pix through NGC 879.
May 7 - 10:
Updated Corwin positions, Dreyer entries and current formatting through NGC 849, added or updated many images and used them to correct several galaxy types and sizes.
Apr 30 - May 6:
Updated Dreyer entries through NGC 799, Corwin positions through NGC 799, adding or updating many images.
Apr 22 - 25:
Updated Dreyer entries through NGC 733, Corwin positions through NGC 749, also adding many images.
Updated Dreyer entries through NGC 655 and Corwin positions through NGC 699.
Apr 16 - 18:
Updated Dreyer entries and Corwin positions through NGC 649, added several images, including an HST image of low-surface brightness galaxy PGC 2699
Apr 12 - Apr 13:
Updated Dreyer entries through NGC 594; also added numerous images.
Updated Corwin positions through NGC 599, and Dreyer entries through NGC 556.
Updated Corwin positions through NGC 549, and Dreyer entries through NGC 541.
Updated Dreyer entries through NGC 499.
Updated Dreyer entries through NGC 465, Corwin positions through NGC 499.
Updated Dreyer entries through NGC 437 (also added several new/better images).
Updated Corwin positions through NGC 449, and Dreyer entries through NGC 425.
Updated Corwin positions through NGC 399, and also Dreyer entries through NGC 399.
Mar 17 - Apr 3:
Adding/checking original Dreyer NGC entries from start of catalog; finished NGC 1 - 369 as of this post. (Have found a few errors caused by mis-copying information from the NGC, so checking my entries for accuracy is critical.) Also doing considerable updating to current catalog format, hence relatively slow progress.
Checking updated Corwin positions from start of catalog; finished NGC 1 - 369 as of this post.
Still working on corrections and updates for NGC 5000 - 5699, but though have made a lot of progress, haven't fully finished any of the pages involved, hence the lack of specific updates; but hopefully posts about finished pages will start showing up by the end of the month.
Working on updates for NGC 5500 - 5549
, 5550 - 5599
. The first page is nearly complete, the second is well under way but still far from complete, and I have just started updating the third. Aside from the obligations noted above, one of the websites that I use as a major reference has been offline more often than not for several weeks, and replacing it is proving difficult, so unless I can find an appropriate work-around, progress on some parts of the NGC/IC catalog will be slower than usual. However, I will continue to update everthing that does not depend on that reference, so though it may take a while before I can say that any given page is truly complete, over a period of time there will be substantial improvements in the catalog.
Added a note to The Heliosphere
about The Edge Of The Solar System
, to clear up a common misconception (due to poorly written news articles) about whether the Voyager spacecraft have left the Solar System or not (they have not).
Added Dreyer's NGC entries to NGC 5500 - 5549
2015 Additions / Changes
Fixed some problems with NGC 5500 - 5549
and posted images of Arp 199
Compared Steinicke's revised database to NGC 5500
Compared Steinicke's revised database to IC 3250 - 3299
. Also posted identifications of NGC 5632
as duplicates of NGC 5691
Compared Steinicke's latest revision of NGC/IC discovery information to my catalog starting at IC 3000 - 3049
through IC 3200 - 3249
Finished adding missing pages (primarily placeholders) for PGC 68000
to PGC 129999
Finished adding Share to Facebook buttons to all existing pages.
Substantially enlarged a biography of Adolphus Albert Le Sueur
, first observer for the Great Melbourne Telescope.
Added a discussion of tidal effects on moons to the page about The Moons of Mars
Corrected a typographical error in one of the equations on the page about Ellipses and Other Conic Sections
Posted a detailed discussion of the Lunar Eclipse Details for Sep 27 - Sep 28, 2015
Started a page containing A List of Solar and Lunar Eclipses
Decided to add a couple of steps to my historical research for NGC/IC objects, to help explain problems with historical identification where they occurred; as a result, all previously so-called "complete" pages may have some minor changes made in the discussion of objects that suffered such problems. Hopefully the result will be to better clarify the problems and their resolution for the benefit of those interested in such things, and readers not interested in the historical discussion can just skip to the physical information and images, as before.
Because of the discovery of a binary black hole in the nearest quasar
, posted images and a discussion of the galaxy involved.
In response to a query, posted a discussion and images of the so-called Sacred Mushroom
Added NGC entries for NGC 3400 - 3449
, NGC 3450 - 3499
, NGC 3500 - 3549
& NGC 3550 - 3599
Posted nearly complete page for NGC 3650 - 3699
, added NGC entries for NGC 3600 - 3649
Posted partially complete page for NGC 3050 - 3099
Posted nearly complete page for NGC 3000 - 3049
Completely finished page for NGC 3100 - 3149
, including updating related PGC pages.
Fixed about a hundred broken links, and added several images of Vesta
Jul 11 - 16:
Posted New Horizons images on Pictures of Pluto
and The Satellites (Moons) of Pluto
Posted false-color "geological"-type images of Pluto
and Charon taken on July 13, 2015.
Completely finished page for NGC 3150 - 3199
, including updating related PGC pages.
Posted the latest images of the "nearside" and "farside" of Pluto
Posted the artwork I created for the cover of my third novel, An Unsuitable Suit
Completely finished page for NGC 2900 - 2949
, including updating related PGC pages.
Completely finished page for NGC 2950 - 2999
May 19 - 22:
Made some corrections on pages for NGC 2000 - 2049
, NGC 3350 - 3399
and NGC 3500 - 3549
Substantially updated page for NGC 2900 - 2949
, which was a nearly blank page; but still needs some work.
Posted an animation of a Martian sunset as seen On The Surface Of Mars
Completed page for NGC 50 - 99
Save for editing confused history of discovery for NGC 16, completed page for NGC 1 - 49
Posted a low-resolution image of the total lunar eclipse
of said date.
Replaced Steinicke's positions for NGC 1
with positions by Brian Skiff and Harold Corwin. Also considerably (though not completely) updated format for the corresponding entries to current standard. Also replaced a number of images with better ones. Also updated Dreyer NGC entries and discovery information for NGC 1 - 120.
Posted a brief discussion of the total lunar eclipse of Apr 4, 2015
, and a link to a detailed image of the circumstances of the eclipse.
Completed a detailed recheck and update of all discovery information for Steinicke and Dreyer for NGC 50 - 99
; will be gradually revising and updating the entire NGC/IC catalog because (1) never finished entering all of Dreyer's entries and (2) Steinicke made hundreds of changes in the latest version of his numerous databases.
Discovered and after some delay fixed a painfully confused historical identification of NGC 57
, which turned out to have been correct in the first place despite the confusion.
Received confirmation that NGC 468
is not IC 92
, but as I suspected a duplicate of NGC 472
; posted essentially final entries for the three objects.
Developed suspicion that the half-century old historical identification of NGC 468 as IC 92 was incorrect; posted temporary revisions.
Working on IC 50 - 99, noticed some discrepancies between my original reference for Dreyer's NGC entries and the actual entries (which were not available to me at the start of this project). Checked IC 1 - 99 against the original Dreyer catalogs, found and fixed a few minor errors. As a result, changed the date for completing IC 1 - 49 to March 11.
Due to an HST press release of Mar 9, added an entry for UGC 8201 (= PGC 45372
). Also (due to starting final update for IC 50 - 99) posted an HST image of Arp 230
, also known as IC 51
Thought I completed the final update for IC 1 - 49
, the first page in my catalog to be completely finished (barring future discoveries); but see the entry for Mar 11.
Started updating NGC 6900 - 6949
Started final update for IC 1 - 49
Posted a page about The Synodic Period of Revolution
, which is the time it takes a planet to move from one aspect to the next occurrence of the same aspect (e.g., from opposition to opposition).
Finally completed the correction of html code, typographical and grammatical errors and the addition of minor updates to all 1200 pages on my website. Most of the errors were so minor that no one should notice any changes; but there were enough of them (and a few major errors) to make the tedious work as worthwhile as it was necessary.
Fixed a typographical error that kept the Polar Animation
page from displaying the animation. Apologies to anyone who tried to view it in the (years?) since the error was introduced.
Added images of constellation figures to Stars and Constellations
Posted a page about Leap Seconds
Feb 4 onward:
Continued to work on updating and editing html code, text and captions for the few remaining pages requiring it (see note of Feb 16 for the worst error uncovered so far).
Posted HST images of NGC 7714
and NGC 7715.
Posted some corrections and clarifications suggested by a private communication.
Jan 31/Feb 1:
Created and/or updated entries for Hickson Compact Group 90
and its members.
Created and/or updated entries for Hickson Compact Group 100
and its members.
Began another round of minor corrections (fortunately mostly very
minor) similar to those of Jan 9 - 21. In doing so, realized that there are significant problems with the identifications of a number of objects on the page dealing with NGC 6450 - 6499
, so added a warning for the six objects in question.
Started updating the page of Messier Nebulae
Finally finished the updating of Messier Galaxies
page started on Dec 27, along with all NGC entries linked to the M-galaxies page.
Jan 9 - 21:
Substantially updated a dozen or two NGC Object
entries due to a private communication pointing out some minor errors in said entries. A couple were due to typographical errors on my part, but most of the errors were due to mistakes in the source material that have been corrected since I copied them. In some cases the mistakes went back more than a century, meaning that similar errors exist in many other databases; as an example, see NGC 7234
. Also updated a number of other entries that were near the ones in question to bring them up to current standards, but nothing worth listing as a separate update.
Posted new HST image of the Pillars of Creation
Updated the page that discusses known display and printing issues (Browser Help
2014 Additions / Changes
Dec 24 - 30:
Continued updating and editing noted for Nov 19 - Dec 23. Starting Dec 27, concentrated on exhaustive updating of Messier Galaxies
and entries on other pages linked to that page. As of Dec 30, about 70% done with the M-galaxy page and linked entries.
Based on new HST image, updated entry for IC 335
Nov 19 - Dec 23:
Continued the updating and editing noted for Nov 4 - 18, and have now completed minor corrections for about 1500 pages, and major alterations for a dozen or so pages. This leaves only a few hundred pages to go, so should return to major additions and updating of NGC/IC entries in early to mid January.
In response to a request, created a complete entry for NGC 5368
In response to requests, created complete entries for NGC 4157
and NGC 7183
Nov 4 - Nov 18:
Working on updating and correcting code for all non-Atlas pages, and fixing numerous minor typographical and grammatical errors.
Added Cassini image of Mimas
to the page about that moon.
Sep 11 - Nov 2:
Updated and corrected code for all 160 NGC Object pages, and updated formatting (and to a lesser extent content) of text, pictures, tags and captions for several thousand NGC entries.
Updated (preliminary) entries for NGC 6353
Did some work on Hickson Compact Groups
and associated pages.
Updated Steinicke discovery/physical data and updated formatting for NGC 1850 - 1899
Added basic Dreyer listings for NGC 1850 - 1899
Updated discovery/physical information and added Dreyer listings for NGC 1750 - 1799
and NGC 1800 - 1849
Posted a major (albeit incomplete) update of page for NGC 1700 - 1749
; also posted a few corrections for NGC 1800 - 1849
Completed updates and second iteration of page for NGC 1600 - 1649
Continued updates for NGC 2050 - 2099
Updated discovery and other information for objects observed by John Herschel at the Cape of Good Hope between 1834 and 1838 (see NGC 2050 - 2099
and NGC 3250 - 3299
Posted animation of the conjunction of Venus and Jupiter
in the morning sky from Aug 14 to Aug 22.
Posted improved discussions and/or images of NGC 1783
, NGC 6365
, NGC 993 = NGC 994
and NGC 3314
Posted numerous additions to NGC 1500 - 1549
, and updated evening planet diagrams for The Wanderers, or "Planetes"
Posted a few additions to NGC 1950 - 1999
Posted minor corrections to IC 2000 - 2049
Posted numerous additions to NGC 1550 - 1599
Updated evening planet diagrams for The Wanderers, or "Planetes"
Posted numerous additions to NGC 3100 - 3149
Posted some additions to NGC 4850 - 4899
Updated diagrams for The Wanderers, or "Planetes"
, and posted partially upgraded version of page for NGC 3100 - 3149
Posted considerably upgraded version of page for NGC 4850 - 4899
Posted preliminary version of page for IC 5250 - 5299
and somewhat updated pages for IC 1000 - 1049
, IC 1150 - 1199
and IC 1200 - 1249
Finished fairly complete version of page for IC 5150 - 5199
and preliminary version of IC 5200 - 5249
Posted entry for PGC 67907
and added diagrams showing the position of "evening" planets to The Wanderers, or "Planetes"
Finished preliminary post for NGC 3200 - 3249
Completed nearly final post for IC 5050 - 5099
Posted images and (updated and corrected) discussion of NGC 5775
Posted images and discussion of NGC 6118
. Also added recent HST image of NGC 201
Recoded page so Maxwell's Equations
are properly displayed in browsers that don't support Symbol.
Posted nearly final page for IC 5100 - 5149
Posted nearly final page for IC 5000 - 5049
Posted nearly final page for IC 4950 - 4999
Posted nearly final page for IC 4900 - 4949
Posted nearly final page for IC 4850 - 4899
Posted diagrams of the total lunar eclipse
of Apr 14/15, 2014.
Added pages providing direct links for every NGC object: NGC 1-2000
Posted nearly final page for IC 4800 - 4849
Posted nearly final page for IC 4750 - 4799
Updated The Oppositions of Mars
to show oppositions through 2020.
Posted nearly final page for IC 4700 - 4749
Posted nearly final page for IC 4650 - 4699
Posted nearly final page for IC 4600 - 4649
Posted nearly final page for IC 4550 - 4599
Posted nearly final page for IC 4500 - 4549
Posted moderately thorough page for IC 4450 - 4499
Posted updated and nearly final version of page for NGC 1 - 49
Posted moderately thorough page for IC 4400 - 4449