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| Date: | 25.3.1998 + 8.3.1997 | Time: | 01h UT + 0h UT | Exposure: | B: 42m, V: 12m, I: 9m, Ha: 20m |
|---|---|---|---|---|---|
| Field of View: | 11' x 9' | Receiver: | HoLiCam, 20482 CCD | Filter: | B, V, I+Ha |
| Instrument: | 1m, f=3680mm | Observatory: | Hoher List | Observer: | S. Kohle, T. Credner |
Astronomical Institutes of the University of Bonn
This three color composit consists of exposures with B, V, I, and H-alpha filters that are represented in blue (B), green (V) and red (I + H-alpha).
This dwarf galaxy is a member of the
Canes Venatici
group of galaxies
and has a distance of about 4 Mpc (12 million lightyears).
The morphology and absolute size is remarkebly similar to our neighbour galaxy
LMC (Large Magellanic Cloud). The bar consists of a population
of stars with an age older than five million years.The red regions in the
upper northern part of the image which emit most of their light in the
H-alpha line are HII regions with embedded
ongoing star formation. There are several bluish white star clusters visible, some of them near filaments of dust which provide the fuel for future star formation. In the western part of the image (right hand side) there is an isolated supergiant shell of H-alpha emission which probably is ionized by the central cluster of stars.
Radio observations in the HI line show that NGC 4449
is embedded in a huge gaseous halo with a diameter of 14 times the optical
one.
References: