Selected Astronomical Catalogues
and Online Data Services
-- and a Few Other Interesting Sites
I have downloaded Gaia DR2 positions for all of the NGC/IC objects
for which they are available and appropriate. I used a one-arcsecond search
radius around the positions previously selected by Brian Skiff and myself, so
if that position was in error by more than an arcsecond, an accurate Gaia DR2
position would not match. I'll clean these up as I check through the position
files over the next few months.
I have finished merging these Gaia DR2 positions into the position files, so I
am pleased to say that the identification and position-determination phases of
the NGC and IC project on which I embarked 40-odd years ago is essentially
complete. A few objects may still, of course, be wrongly identified, or have
poor coordinates, but the vast majority are now correctly positioned on the
The results of all this are found in the
NGC/IC section of this web site. See the
Introduction there for details and
suggestions on accessing the data.
I am now beginning to collect other data for these objects, types, magnitudes,
diameters, redshifts -- whatever information are appropriate for
characterizing each object. Until I can get that done,
Steve Gottlieb, and
Seligman have collected data for most of the NGC and IC objects. I'm
pleased to be able to point you to their NGC/IC pages.
In most cases, the Gaia DR2 positions are the "best" available, agreeing well
with positions from earlier astrometric lists (e.g. UCAC, URAT1, 2MASS, SDSS,
Pan-STARRS1, etc.), so I have selected the DR2 positions when they are
appropriate for the objects. However, in addition to those objects with
selected positions more than an arcsecond from the Gaia DR2 positions, some of
the stars in the lists have proper motions that have moved them beyond my
initial one arcsecond search radius. I have already looked at many of these,
and -- like the NGC/IC objects themselves -- will cover the others as I
continue to check the lists.
I should mention here that the Gaia team has recently found that DR2 positions
have a systematic offset with respect to the ICRS (defined by QSOs) on the
order of 30 microarcseconds (see e.g.
Lindegren et al.,
Arenou et al., 2018). This is far below the precision which I have
adopted (10 milliarcseconds) for display here, so the practical consquences
for this list are negligible. It is also possible that galaxy nuclei are
measured less accurately than stars because of the surrounding envelope of
light from the main body of the galaxy. However, to my knowledge, this
remains to be rigorously tested.
I also encourage you to check the positions yourselves as you use the files; I
make enough mistakes that I am certain that these files are not
bug-free. I recommend CDS's
for this -- search in catalogue number I/345/gaia2. I also recommend checking
the Gaia positions against those in the first Pan-STARRS data release,
catalogue number II/349 in VizieR, or any of the other astrometric catalogues
included in VizieR.
As usual, I have benefitted from correspondence with Steve Gottlieb, Courtney
Seligman, and Steve Waldee on several of the NGC/IC objects. I'm pleased to
thank them once again for their help.
Here are some notes from previous releases of these files that are still
Brian Skiff and I have now selected accurate positions for all of the NGC and
IC objects. These are in the current versions of my
NGC/IC position and notes files which are
available here, as are positions and notes for about 200 non-stellar
objects (or objects thought to be non-stellar) that were known before the NGC
was published, but not included in it.
There are still many checks to be done, and a full comparison with the
original positions also remains. Finally, as I mentioned above, I am
committed to providing data (particularly magnitudes and diameters) for all of
the objects, too. So, check back now and then for updates. I'll announce
them on the "amastro" mailing list as they become available, so you could
check there as well.
UBVRI Photometry of Galaxies, Globular Clusters, and Stars
In a previous release, I presented the results of my photomtery observing
runs at McDonald Observatory. The data consist of large-aperture photometry
for 239 nearby galaxies, 18 Galactic globular clusters, more than 550 stars, a
few miscellaneous objects, and a new set of secondary standard stars, all in
the Johnson/Cousins (UBV)J(RI)C system.
McDonald UBVRI photometry, 1982-1988
has the details and the data.
I've had requests to combine the tables of positions and final magnitudes,
particularly of the stars. I have done this, and those tables are now
available. Again, the directory cited above
has the details and the new tables.
Extragalactic Catalogues Maintained by Harold G. Corwin, Jr.
The copies of
The Third Reference Catalogue of Bright
Galaxies, by G. de Vaucouleurs, A. de Vaucouleurs,
H.G. Corwin, R.J. Buta, G. Paturel, and P. Fouqué
A Catalogue of Rich Clusters of Galaxies
, by G.O. Abell, H.G. Corwin, and R.P. Olowin,
A Southern Galaxy Catalogue
by H.G. Corwin, A. de Vaucouleurs, and G. de Vaucouleurs,
found here are corrected versions of the published catalogues. Though all
three have been available as printed and bound books, the electronic versions
here are preferred for reference as all known errata occuring in the printed
versions have been corrected. Please let me know if you find any further
Brief explanations of the data are also available electronically; the full
introductions with figures, tables, and references are only available in the
A final version (1.4.3) of
A South-Equatorial Galaxy Catalogue
by Harold G. Corwin, Jr. and Brian A. Skiff
is also available. This has accurate positions, diameters, position angles,
and de Vaucouleurs revised Hubble-Sandage (VRHS) types for 3333 single or
multiple galaxies in the south-equatorial declination zones between +3 degrees
and -21 degrees. The data were gleaned from POSS1 103a-O copy plates, then
checked against the UKST IIIa-J portion of the DSS. The corrected position
angles and VRHS types are published here in full for the first time. Notes on
the individual objects are also available. SEGC provides a finding list for
galaxies generally larger than about 1.8 arcmin at the 25.0 B-mag arcsec^-2 in
the south-equatorial zone between the southern limit of the CGCG and UGC, and
the northern limit of ESO-B, ESO-LV, and SGC. It provides a somewhat
shallower coverage of this part of the sky than MCG, but acts as a second link
between the northern and southern galaxy surveys.
All of these catalogues are freely accessible; my coauthors and I ask only
for a reference and/or an acknowledgment if you use data from them.
Links to Useful Astronomical Web Sites
Most of these Web sites are devoted to astronomical cataloguing and data
NED -- NASA/IPAC
Virtual Observatory on the Web
The NASA Astrophysics
MAST -- The Space Telescope Science
Institute HST Data Archive
The Canadian Astronomy
The ESO/ST-ECF Science Archive
Brian Skiff's FTP directory at
Lowell Observatory with hundreds of files of useful data
Steve Gottlieb's NGC/IC web pages
Steinicke's Home Page, with links to his historical work
on the observations leading to the Dreyer's NGC and IC
Steinicke's biographical information for the NGC/IC
Celestial Atlas featuring images and notes for many
celestial objects, including the
NGC and IC objects
Seligman's list of refrences and links to NGC/IC observer biographies
and published papers
Steve Waldee's astronomy web pages
The NGC/IC Project
The Webb Deep Sky Society
Links to Classical Music Web Sites
The Source for Classical Music is a clearing house for
virtually all of the distributors of recorded classical music in the
USA. I use their service frequently; it is fast and reliable. If
there are problems (I've had just two in the past decade), their
customer service reps will fix them quickly. They do downloads as
well as physical media, and have begun a streaming service as well.
They also have agreements with many record companies to make deleted
issues available as on-demand CD-Rs.
Fanfare -- The Magazine for
Serious Record Collectors. If you have any interest at all
in listening to classical (or even jazz) recordings, this magazine is
for you. Published every two months, it is packed with reviews of
most of the classical music recordings released in the US. The
reviewers write knowledgeable and interesting reviews, and there is
an on-line archive of the magazine's reviews and feature articles
since it began publication in 1977.
Brian Society promotes the music of the 20th century English
composer and critic Havergal Brian. I must confess that I find his
orchestral music fascinating and frustrating all at once.
Tonally-based and superbly orchestrated, his music is nevertheless
among the more difficult that I have tried to get a grip on. Brian's
works overflow with ideas, and often burst through the usual formal
constraints of symphonic music. The disconcerting result is that I
am often lost among the trees while trying to make out the overall
patterns of his wonderful forests of sound.
The Ralph Vaughan Williams
Society. I have no such problems with Ralph Vaughan
Williams's music; I have loved it unconditionally since I first heard
his 5th Symphony in the early 1960s. I had seen this Society
mentioned in several of the music magazines I subscribe to, and had
wondered at its intent. Vaughan Williams, after all, is -- along
with Sir Edward Elgar -- the composer most responsible for the
renaissance of English music in the first half of the 20th century.
Many of his works are are among the greatest of that century, and are
recorded frequently, so why does this Society exist? As it happens,
Vaughan Williams's well-known music is just a portion of his
considerable output over his long composing career (the early 1890s
until his death in 1958). The RVW Society promotes performances and
recordings of Vaughan Williams's lesser-known music -- some never
performed before -- and has issued thirty (so far!) recordings on its
own "Albion" label. "Vaughan Williams," by the way is an
unhyphenated double last name; others like it (e.g. "Maxwell Davies")
are relatively common in Great Britain.
The Buffalo Philharmonic Orchestra
is our orchestra. While perhaps not quite in the top rank of
orchestras in the world, the BPO is just down the road from us, and
we are lucky to be living in a city that supports it. They have many
recordings available, most with their long-time conductor JoAnn
Falletta, that demonstrate their versatility. In my opinion, almost
all of the recordings are worth adding to your collection. Buying
the recordings directly from
the BPO makes a contribution to the orchestra as well as
providing you with a fine CD.
Links to Railroading Web Sites
Amtrak -- the National Railroad
Passenger Corporation provides intercity passenger train
service in the US. We are fortunate to have an Amtrak station within
a few miles of our home, so we travel by train when we can.
The Rail Passengers Association
(formerly NARP -- the National Association of Railroad
Passengers) is a primary voice in Washington, DC speaking on behalf
of train and rail commuter passengers. NARP has some considerable
clout in helping to keep Amtrak going.
ESPA -- the
Empire State Passengers Association has moved its main web
presence to Facebook. Just as NARP is an organization devoted to
promoting rail travel across the United States, so is ESPA "working
for better rail passenger service and public transportation in New
York State." In principle, ESPA promotes transportation initiatives
across the entire state, but it seems to be primarily focused on
Upstate issues affecting passenger travel outside the New York City
Southern Pacific Historical &
Technical Society is dedicated to preserving and
disseminating the historical record of the Southern Pacific Railroad
and its affiliates. The Southern Pacific was "my" childhood railroad
in California, and I renewed my attachment to it during my twenty
years there between 1991 and 2011. SPH&TS publishes "SP Trainline"
four times a year. Yes, the magazine is a nostalgia trip for me,
with a strong focus on the railroad itself. But the "Espee" is also
an important element in the history of the western United States.
"Trainline" often provides that broader context.
Model Railroading is a glimpse
inside the mind of an atypical model railroader. I call myself
"atypical" because I have no layout where I can actually run my
trains, and no large space where I can even contemplate building such
a layout. Nevertheless, I have a lot of rolling stock, almost all
modeled from Southern Pacific prototypes (see above) or from Amtrak
prototypes (also see above). Once in a while, I will report on my
model railroading activity in this space. At the moment, this
directory has before and after photos of an HO model of a single
Amtrak passenger car that I've recently modified, as well as a link
to a photo of the prototype.
The previous version of this site was made possible by the
and Analysis Center, which is operated by the
Laboratory and the
California Institute of Technology, under
contract with the National Aeronautics
and Space Administration. I am pleased to acknowledge their
support prior to my retirement in July 2011.
that earlier version of this site which will serve as an archival
snapshot of the catalogues as they existed when I loaded them into NED.
I use GoDaddy for hosting and
domain services. They offer far more than I need, but what I do need from
them is easy to use and reliable.
Latest update: 16 August 2019