BILLIONS OF STARS IN MESSIER 33 (HDR)
|(CLICK REFRESH ON YOUR BROWSER IF IT DOESN'T APPEAR)|
Equipment and exposition:
GSO RC 8" F/8
ATIK 383L+ with Orion Nautilus Usb filter wheel, Astronomik Filters 50,8
Guided with Starlight Lodestar with Orion OAG
Neq6 Geoptik Modded
L : 12 X 600 Secs.
RGB : 8 x 600 Sec.s (Each channel)
Processed with PixInsight ,Maximdl,Photoshop CS4
SIte : Val Troncea ,West Alps. Italy 29/09/2011
About this object:
he Triangulum Galaxy is a spiral galaxy approximately 3 million light years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC 598, and is sometimes informally referred to as the Pinwheel Galaxy, a nickname it shares with Messier 101. The Triangulum Galaxy is the third-largest member of the Local Group of galaxies, which includes the Milky Way Galaxy, the Andromeda Galaxy and about 30 other smaller galaxies. It is one of the most distant permanent objects that can be viewed with the naked eye.
With a diameter of about 50,000 light years, the Triangulum galaxy is the third largest member of the Local Group, a group of galaxies which also contains the Milky Way Galaxy and the Andromeda Galaxy, and it may be a gravitationally bound companion of the Andromeda Galaxy. Triangulum may be home to 40 billion stars, compared to 400 billion for the Milky Way, and 1000 billion stars for Andromeda
Estimates of the distance to the Triangulum galaxy range from 2,380 to 3,070 kly (730 to 940 kpc), with most estimates since the year 2000 lying in the middle portion of this range. At least three techniques have been used to measure distances to M 33. Using the Cepheid variable method, an estimate of 2,770 ± 130 kly (850 ± 40 kpc) was achieved in 2004. In the same year, the Tip of the Red Giant Branch (TRGB) method was used to derive a distance estimate of 2,590 ± 80 kilolight-years (790 ± 25 kpc).
In 2006, a group of astronomers announced the discovery of an eclipsing binary star in the Triangulum Galaxy. By studying the eclipses of the stars, astronomers were able to measure their sizes. Knowing the sizes and temperatures of the stars they were able to measure the absolute magnitude of the stars. When the visual and absolute magnitudes are known, the distance to the star can be measured. The stars lie at the distance of 3,070 ± 240 kly (940 ± 74 kpc).
The Triangulum galaxy is a source of H2O maser emission. In 2005, using observations of two water masers on opposite sides of Triangulum via the VLBA, researchers were, for the first time, able to estimate the angular rotation and proper motion of Triangulum. A velocity of 190 ± 60 km/s relative to the Milky Way was computed, which means Triangulum is moving towards Andromeda.
The Pisces Dwarf (LGS 3), one of the small Local Group member galaxies, is located 2,022 kly (620 kpc) from the Sun. It is 20° from the Andromeda Galaxy and 11° from Triangulum. As LGS 3 lies at a distance of 913 kly (280 kpc) from both galaxies, it could be a satellite galaxy of either Andromeda or Triangulum. LGS 3 has a core radius of 483 ly (148 pc) and 2.6 × 107 solar masses