Home     Getting Started     To Survive in the Universe    
Inhabited Sky
    News@Sky     Astro Photo     The Collection     Forum     Blog New!     FAQ     Press     Login  

IC 1947



Upload your image

DSS Images   Other Images

Related articles

The Southern Dwarf Hunt: Local Group Dwarf Candidates in the Southern Sky
We present observations of 82 Local Group dwarf galaxy candidates, ofwhich 62 were chosen visually from ESO-SRC survey plates of the southernsky (32 of which were not previously cataloged) and the rest suggestedby various sources in the literature. Two are the Local Group galaxiesAntlia and Cetus; nine are more distant galaxies, though still within afew megaparsecs; 45 are background galaxies; seven are planetary (orother emission) nebulae; 15 are reflection or other Galactic nebulae;two are galaxy clusters; one is a Galactic star cluster; and one is amisidentified star. We conclude that there is no large population offaint Local Group dwarf galaxies of any familiar type awaitingdiscovery. We point out the danger of relying on a single type of datato reach conclusions about an object. Based on observations made withthe Isaac Newton Telescope, operated on the island of La Palma by theIsaac Newton Group in the Spanish Observatorio del Roque de losMuchachos of the Instituto de Astrofísica de Canarias, and onobservations made at Cerro Tololo Interamerican Observatory (CTIO). CTIOis operated by the Association of Universities for Research inAstronomy, Inc. (AURA), under a cooperative agreement with the NationalScience Foundation as part of the National Optical Astronomy Observatory(NOAO).

Total magnitude, radius, colour indices, colour gradients and photometric type of galaxies
We present a catalogue of aperture photometry of galaxies, in UBVRI,assembled from three different origins: (i) an update of the catalogueof Buta et al. (1995) (ii) published photometric profiles and (iii)aperture photometry performed on CCD images. We explored different setsof growth curves to fit these data: (i) The Sersic law, (ii) The net ofgrowth curves used for the preparation of the RC3 and (iii) A linearinterpolation between the de Vaucouleurs (r(1/4) ) and exponential laws.Finally we adopted the latter solution. Fitting these growth curves, wederive (1) the total magnitude, (2) the effective radius, (3) the colourindices and (4) gradients and (5) the photometric type of 5169 galaxies.The photometric type is defined to statistically match the revisedmorphologic type and parametrizes the shape of the growth curve. It iscoded from -9, for very concentrated galaxies, to +10, for diffusegalaxies. Based in part on observations collected at the Haute-ProvenceObservatory.

Dynamics of the Pavo-Indus and Grus clouds of galaxies
A study of groups of galaxies in the above regions was carried out byselecting a sample extending one magnitude deeper than previous work inthe area, complete down to 15 mag. We report new redshift determinationsfor 58 galaxies in the region and 13 other miscellaneous galaxies, basedon La Silla observations. Using a total of 266 galaxies with measuredredshifts in the Pavo-Indus and Grus clouds, we perform a new analysisof groupings following a well-tested algorithm. A total of 18 groups issingled out, most of them known from previous work, even though a fewadditional members are added. For all the groups, we have calculateddynamical parameters and M/L ratios. All groups are found to be boundaggregates, but only one group can be virialized. For the six mostpopulated examples, having at least five members, we also calculateseveral mass estimators and discuss the wide range of observed M/Lratios, which extends from nine to nearly 500 M(solar)/L(solar). Weintroduce two parameters to measure the presence of either a dominantgalaxy or internal subcondensations, respectively, and test whether anycorrelation with the M/L ratios can be detected. No clear correlationsare found.

Nearby galaxies. I - The catalogue
The data of 289 nearby galaxies have been compiled. The inclusion of agalaxy into the catalog depends on its redshift as in the catalogue ofKraan-Korteweg and Tammann (1979) or on the fact that the objects areknown to be certain or probable members of nearby groups. The galaxiesin the sample form the Local Group with 51 certain and probable membersand several additional groups. One third of the galaxies in the catalog(96 objects) does not seem to belong to any group. The main emphasis isto get a distance-limited sample of galaxies, especially of dwarfobjects.

New nebulae and nebulous stars.
Not Available

Submit a new article

Related links

  • - No Links Found -
Submit a new link

Member of following groups:

Observation and Astrometry data

Right ascension:03h30m32.70s
Aparent dimensions:0.575′ × 0.479′

Catalogs and designations:
Proper Names   (Edit)
ICIC 1947

→ Request more catalogs and designations from VizieR