Distance: 11 Million Light Years
Size: 21 x 20 Arc-minutes
Age: Approx. Several Billion Years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 25×600 Bin 1, RGB 20×300 Bin 2, Ha 16×900 Bin 1
IC 342 is a spiral galaxy in the constellation Camelopardalis. It is a member of the neighboring IC 342/Maffei galaxy group. While it is the largest galaxy in its group, it is about half the size of our Milky Way galaxy. IC 342 is located about 10 degrees above our galactic plane and therefore we must observe it looking through some dense regions of our own Milky Way galaxy. Our galactic dust and gas obscures IC 342 making it appear slightly reddish brown and this dust also dims the galaxy by 2.4 magnitudes. All of the stars in my image are foreground stars and are part of the dense star field of our Milky Way galaxy. I think this provides a great field of view at the right focal length.
IC 342 is an SAB(rs)cd galaxy. The SAB means it is a spiral galaxy with a slight bar. The (rs) means that there is a slight ring around the core and the cd describes how tightly wound the arms are. The galaxy is rotating counter-clockwise based on the shape of the arms. The majority of the arms contain gas and dust regions which are full of very hot and very young stars. The arms also contain several HII regions which are star forming regions and can be seen as reddish blobs in my picture. The core of IC 342 is also a region of high star formation and is a popular target for research.
This image was captured from my home in a Bortle 6 zone.
Distance: 10 Million Light Years Telescope: 10” RC
Magnitude: 8.9 Camera: QSI 683
Size: 11 x 10 Arc-minutes Mount: AP 900
Age: Approx. 10 Billion Years Exposures: L 10×900 Bin 1, RGB 10×450 Bin 2
NGC 6946, the Fireworks galaxy, is a spiral galaxy in the constellation Cepheus. It is a relatively large face on spiral galaxy that lies along the galactic plane and it is this view through the galactic plane that presents the rich foreground star field. The asymmetrical shape of NGC6946 may be the result of earlier gravitational interactions with nearby galaxies. Classified as a type Sc galaxy, NGC 6946 has well defined arms containing star clusters, Ha regions, and dust lanes. There is a lot of active star formation in NGC 6946. It is not clear what is causing this as there hasn’t been any recent interaction with other nearby galaxies. One thought is the spiral galaxy has a strong nuclear bar at its core. The bar shape is formed as the orbits of nearby stars become unstable and become elliptical. More and more stars follow this pattern and the bar shape becomes more defined. The formation of this bar is thought to induce star creation in the surrounding gas by concentrating it in the core area.
NGC 6946 is also called the Fireworks galaxy. This is in part because of the high star formation rate but also because of the large quantities of supernovas. From 1917 to 2009 there have been nine supernova, by comparison our Milky Way galaxy averages one per century. There is also a large halo of gas that extends out from the galaxy disk and it is thought that this halo is the ejected neutral gas resulting from the high rates of star formation and supernova.
[SEDS, University Today]
Distance: 12 Million Light Years
Magnitude: Messier 81 Magnitude 6.9, Messier 82 Magnitude 8.4
Size: Messier 81 21 x 10 Arc Minutes, Messier 82 9 x 4 Arc Minutes
Galaxy Type: Messier 81 Spiral, Messier 82 Starburst
Telescope: Televue NP101
Camera: QSI 683
Mount: AP 900
Exposure: L 17×600 Bin 1, RGB 17×300 Bin2
Messier 81 is a spiral galaxy in the constellation Ursa Major. M81 is the larger galaxy at the bottom of my picture and is about 12 million light years away. With a diameter of 70,000 light years and at magnitude 6.9 it is one of the brighter galaxies and shows well in short exposures. M81 also contains a super massive black hole at its core that is about 15 times larger in mass than the one in our galaxy. The core itself is much larger than the core of our galaxy and contains many older reddish color stars. The spiral arms contain large amounts of dust and gas and are active star formation regions with young blue stars that give their arms their color.
Messier 82 is a spiral galaxy type known as a star burst galaxy in the constellation Ursa Major. M82 is the smaller galaxy directly above M81 and also lies about 12 million light years away. A star burst galaxy is a galaxy that has had a gravitational interaction with another galaxy. In this case it was with M81 several hundred million years ago with the two galaxies presently about 150,000 light years apart. The area above and below the core show these starburst areas and appear as if they are exploding out and away from the galaxy core. Their reddish color and several dust lanes stand out from the rest of the bright galaxy. The Hubble Space Telescope has discovered over 100 young globular clusters in this galaxy and this was probably the result of the interaction with M81 several hundred million years ago.
M81 and M82 are part of the M81 galaxy group that also includes 32 other galaxies located in the constellations Ursa Major and Camelopardalis. There is another galaxy that is also interacting gravitationally with M81 called NGC 3077. It is thought that NGC 3077 is partially responsible for the star development in M81. NGC 3077 is the fuzzy galaxy in the lower left corner of my image.
[Hubble, SEDS, Wikipedia]
Distance: 2.9 Million Light Years Telescope: Televue NP101 + .8 Reducer
Magnitude: 3.4 Camera: QSI 683
Size: 178 x 63 Arc Minutes Mount: AP 900
Galaxy Type: Spiral Sab Exposure: L 14×300 Bin 1, RGB 14×300 Bin1
Messier 31, also known as the Andromeda galaxy is a large spiral galaxy and is home to about 1 trillion stars. It is about 250,000 light years in diameter and is also the largest galaxy in our local galaxy group which consists of the Triangulum galaxy, Milky Way galaxy, and 44 other galaxies. Some recent studies suggest that our Milky Way galaxy may actually be denser than the Andromeda galaxy even though our galaxy is much smaller. The Hubbell Space Telescope discovered what appear to be two galactic cores. One thought is that there are actually two galactic cores perhaps caused by an earlier interaction between two galaxies. The other thought is that there is only one core but it appears as two cores due to dark dust clouds partially obscuring the view. The Andromeda galaxy contains globular and open star clusters, Ha nebula regions, planetary nebula, super nova, and other objects found in spiral galaxies.
M31 contains the largest observed globular cluster known as G1. This cluster contains several million stars and is twice as luminous as Omega Centauri (the largest and brightest globular in our galaxy). To date, there have been about 460 globular clusters discovered in M31. The globular clusters in M31 range in age from several million years to about 5 billion years while the ones in our galaxy typically are over 10 billion years old. There is also a very large star cloud that has its own NGC designation, NGC 206, and is visible in my image in the top left corner of the galaxy arm.
As with most spiral galaxies there are several Ha regions contained within the spiral arms. These areas are where star formation is actively occurring and many in M31 can be seen with amateur telescopes and CCD cameras. A recent paper [Univ. of Western Ontario Aug 2011] states 3,691 Ha regions have been discovered in this galaxy.
To the bottom left of the galaxy is Messier 110. This is a small elliptical galaxy and from Earth is about the same distance as M31, 2.9 million light years. At magnitude 8.5 it is to dim to see with the naked eye. This galaxy is also a satellite galaxy of M31 which means it is gravitationally bound with M31. There have been 8 globular clusters found in this galaxy and there are also a few dust lanes apparent in images captured with larger telescopes.
Directly above the core of M31 is Messier 32. This is a small elliptical galaxy and it is also gravitationally bound with M31. Its distance from Earth is about the same as M31 and M110 at 2.9 million light years. At magnitude 8.1 it can’t be observed with the naked eye. As with most elliptical galaxies M32 is old and there are not a lot of Ha regions where new star formation is occurring.
[Info from SEDS and Wikipedia]
Distance: 2.7 Million Light Years Telescope: Televue NP101
Magnitude: 5.7 Camera: QSI 683
Size: 73 x 45 Arc Minutes Mount: AP 900
Galaxy Type: Spiral Scd Exposure: L 20×600 Bin 1, RGB 20×300 Bin2
M33, also known as the Triangulum Galaxy is located in the constellation Triangulum. It is a face on spiral galaxy that is part of our local galaxy group which also contains the Andromeda galaxy and 44 other smaller galaxies. The Triangulum galaxy is the third largest galaxy in our local group at about 50,000 light years across and is thought to contain around 40 billion stars. For comparison our Milky Way galaxy is thought to have about 400 billion stars and the Andromeda galaxy contains about 1 trillion stars. At a distance of about 2,700,000 light years it is roughly the same distance as the Andromeda galaxy. M33 is moving towards our solar system at about 24 kilometers per second but there is uncertainty if there will ever be a collision and even if it does occur it will happen in several billion years.
The galaxy has distinct spiral arms but appears to be partially clipped on one side and at first I thought my calibration routine may be at fault. The sudden change in brightness is seen on the left side of my image and almost takes the form of a hard line. I compared my image to some others on the internet and it appeared normal but I don’t know why there is this sudden change in brightness. There are several areas of Ha emission nebula where new star formation is occurring and the larger ones have their own NGC and IC names. The largest of these is NGC 604 and can be seen as a reddish glow in the upper left of my image. There are also over a hundred globular clusters that have been identified. These clusters contain many hot blue young stars and indicate that they are several billion years old. Other objects that have been observed include over 25 Cepheids and several supernova remnants. There was a also a black hole discovered at the center of the galaxy in 2007 and its size was estimated at about 15 times the size of our sun.
Info collected from Wikipedia and SEDS.org
Annotated version below.