Astro Images with side notes
- 1. Astro-Imaging by David Evans If you are viewing this from my LinkedIn profile, I bid you a warm welcome. I thought I would do something different and show one of my interests here. That is, astronomy, and taking images of some of the myriad objects in the sky. Take a look and enjoy.
- 2. Equipment The concrete base is around 1 ton. Mount: Paramount ME (a.k.a. Red Cube) from Software Bisque. The mount is computer controlled from the room you see through the door. This is called a “warm room,” which is an absolute necessity in winter. It contains a propane heater. Optical Tube Assembly: Meade 12” LX200ACF Schmidt telescope at f6.7. Secondary scope: Televue Genesis, 101mm at f5. This is the white telescope on top of the big blue one. Guide camera: Orion Starshoot Autoguider Main Camera: SBIG ST8XME. Observatory: 12' X 24' with roll off roof and 8' X 10' warm room. Needless to say, the structure is quite long, and there are two of us who have our mounts in the structure.
- 3. Jupiter – Largest Planet of Our Solar System Some basic facts about our fifth planet from the sun. Average distance from Sun: 483,682,210 miles. Diameter: 88,800 miles. Over 11 times larger than the Earth's diameter. Gravity is approximately 2.14 times that of Earth. If you weigh 100 lbs here, on Jupiter you would weigh 214 lbs. The volume of Jupiter would hold 1200 Earths. A day is almost 10 hours. The Galilean Moons you see in the image are from most inner to outer: Io, Europa, Ganymede, Callisto. Galileo discovered them in 1610. No other moons were discovered until 1892. Almost 300 years after the first 4 were seen!
- 4. M13 – The Great Globular Cluster In Hercules The M in M13 stands for Messier. Charles Messier, a French astronomer, was the first to “catalog” the object in 1764 in the constellation of Hercules M13 was originally discovered in 1714 by Edmond Halley. M13 is what is known as a globular cluster and is outside of the Milky Way Galaxy. It is 25,000 light years away, and is 145 LY's across. It is comprised of several hundred thousand stars. The galaxy in the top right is known as NGC 6207. If you look very close at the image, about halfway to NGC 6207, there is another faint galaxy known as IC 4617.
- 5. NGC 884 and NGC 869 - The Double Cluster The distance to the clusters are 7600 and 6800 light years. These are very young stars as the Universe goes. They are 3 and 6 million years old, respectively. NGC 884 and 869 are known as open clusters due to the loose gravitational association the stars in them have to one another, In addition, they were all formed of the same molecular cloud, and are all nearly the same age. If you look at the constellation of Perseus, you would be able to see these objects, as they are able to be seen with the naked eye, In essence, one does not need a telescope to see them on a dark night at a good site. That said, it still helps to see their beauty more fully.
- 6. M57 - The Great Ring Nebula M57 is the 57 th object cataloged by Charles Messier. He originally made his famous catalog because he was hunting for comets, and he needed to know what objects to avoid in order to not mistake them for what he was searching for. The distance to M57 is approximately 2300 light years in the constellation of Lyra, and is is around 1.3 light years in radius. M57 is around 1600 years old. It is an example of what is known as a planetary nebula. A low mass star much like our own got old and sloughed off its outer layers. The star became a white dwarf, and will ultimately die many billions of years from now. It is able to be seen in the very middle of the nebula.
- 7. M76 - The Little Dumbbell Nebula M76 is another example of a planetary nebula. The image you see here was colorized to show a little more detail and to give greater aesthetic value. It is about 2500 light years away, and about .6 light years across. As a star dies, it grows in size and becomes a red giant. Our star when it runs out of fuel in about 4 to 5 billion years will grow to about the size of the orbit of the Earth. It may even incorporate the Earth's orbit. As the outer layers are flung away out into the void, the material will be used to make new stars and planets elsewhere in the Galaxy. Ultimately, our Sun will become a white dwarf, grow old, and finally fade into obscurity.
- 8. M27 - The Dumbbell Nebula Another example of a planetary nebula, and to show comparison to M76.
- 9. NGC 6781 – A Planetary Nebula
- 10. NGC 7635 – The Bubble Nebula NGC 7635 (NGC is short for New Galactic Catalog) is known as an emission nebula. It is in the constellation of Cassiopeia, lies around 11,000 LY's away, and is about 5 LY's in diameter. It is formed by a very hot star exerting pressure on the surrounding gas through the extreme radiation it emits. The image was taken with a hydrogen alpha filter. This is a filter that only allows a specific wavelength of light through in which to capture an image. It is often what one has to use when the Moon is in the night sky, as the reflected light will ruin normal light gathering images.
- 11. M20 – The Trifid Nebula This is another example of an emission nebula, but it has a twist. It is also a reflection nebula. Where the emission nebula is light being emitted by ionized gas due to a hot star, a reflection nebula is due to the result of light being reflected by the clouds of gas from the light of a nearby star. If this image was taken using red, green, and blue filters, you would be able to see the reflection nebula as blue surrounding the bright star at the edge of the frame to the right. The object is about 7600 LY's away, in the constellation of Sagittarius,
- 12. M16 – The Eagle Nebula The so called Eagle Nebula got its name due to its vague shape resembling an eagle. It is an emission nebula. Look closely at the heart of the image, you will see what has often been called the Pillars of Creation from the famous image taken by the Hubble Space Telescope. The pillars are star forming regions; where new stars are being born. This region lies in the constellation of Serpens, is 7000 LY's away, and is around 15 LY's across.
- 13. M8 – The Lagoon Nebula Another example of a star forming region, is between 4000 to 6000 light years distant. The dimensions of the nebula are 110 x 50 light years in size. M8 is situated in Sagittarius. The constellation is also called the Teapot due to the shape the asterism forms. An asterism is a gathering of stars that form a pattern to which we attach meaning. When viewing the constellation, one is looking in the direction of the galactic core. At the core, there exists a massive black hole that is 2.6 million times the mass of our Sun. It lies around 66,000 light years away. We are about two thirds of the way out from the center of the Milky Way Galaxy, which is estimated to be 100,000 to 120,000 light years in diameter.
- 14. M101 – The Pinwheel Galaxy This is a galaxy in the constellation of Ursa Major (the asterism of the Big Dipper makes up this constellation), and is 23 million light years away. M101 is nearly twice the size of our galaxy at 170,000 light years across. Its asymmetry is thought to be due to a past collision and incorporation of another galaxy. The photons of light that made up this image had to travel 23 million years to reach the CCD chip of the camera. This image is due to the summing of data from 19 two minute images. The nice aspect of using a CCD camera is that data is able to be added together. So the total time of this image is 19x2=38 minutes.
- 15. NGC 6946 – The Fireworks Galaxy Needless to say, without an image being in color, one is not able to see appropriately the colors that can show up in this object. The galaxy sits on the border between the constellations of Cepheus and Cygnus. It's light took 22 million years to reach us. Since 1917, we have been able to see 9 supernova explosions in NGC 6946. A supernova is when a massive star explodes and ejects either all or most of its material. There are several types, but there is one known as a Type Ia. It gives us a standard candle of brightness that allows us to measure the distance to galaxies far, far away. Some supernovas result in the the creation of neutron stars or in a black hole.
- 16. M51 – The Whirlpool Galaxy An Image Using The Televue Genesis M51 is a popular galaxy to both view and image for astronomers. It resides in the constellation of Canes Venatici, and is 23 million light years away. The main disk of M51 is approximately 38,000 light years across. One aspect to note is that it is interacting with a smaller dwarf galaxy. The dwarf galaxy (NGC 5195) has already passed at least once through the main disk about 500 to 600 million years ago. From recent simulations, the thought is that NGC 5195 made a disk crossing as recently as 50 to 100 million years ago, and is now coming towards us from behind M51. It will ultimately be cannibalized and eaten by the larger galaxy. If you look closely at the dwarf galaxy. It shows stars being torn off and strewn out into intergalactic space to the left of the image. Some will never return... Note the scale of the image from using the smaller telescope to image from. Compare it to the image you see on the next slide showing the same galaxy.
- 17. M51 - Through 12 Inch Meade LX200ACF 24 x 10 minute sub-frames Total time with luminance, red, green, blue filters is 240 minutes or 4 hours.
- 18. M81 and M82 Through Televue Genesis Both of these galaxies are in Ursa Major (remember that the Big Dipper is a part of that constellation). Both are about 11.5 million light years away, and are interacting gravitationally. Due to the interaction, filaments of hydrogen gas have been stripped from each of them. Also, more interstellar gas has fallen into the center of M82 (left) and has caused a lot of new star formation to occur. To the point that, with a much longer exposure time, M82 would look as if it was exploding from its center due to the particle winds of so many stars being born, as well as going supernova.
- 19. NGC 7331 Information In this image of over 5 hours, you see at least 4 different “obvious” galaxies. The largest one is NGC 7331. Above the large galaxy you see from left to right: NGC 7335, 7336, and 7337. There is a fifth galaxy that is part of this group, but it was not included in the imaging session. The group is also given the nomenclature of the “Deer Lick Group.” These objects are in the Pegasus constellation. NGC 7331 is 40 million light years away. One aspect to stress here. Anything you view in the sky; a planet, a star, a nebula, a galaxy, are all being viewed in the past. You are, in a sense, time traveling to the past. The main galaxy here has another distinction in that the central bulge is rotating counter to the rest of the disk. At this time, it is unknown as to why this is occurring. On the next slide you will see a larger image of the galaxies.
- 20. NGC 7331 – A Bigger Image Is Better
- 21. Stephane's Quintet Here you have 6 galaxies being shown together. The one along the bottom about a third of the way over from the left is not a part of the group above. It is a much closer and smaller object. The 4 above are all interacting together and will most likely come together to form one huge galaxy. There is another galaxy at about the 1:30 position as compared to the 4 galaxies below it. This galaxy group, like the Deer Lick Group, are in the Pegasus constellation. This group is a rather faint object to image. This is in part due to the distance away from us. The 4 main galaxies are nearly 300 million light years away. That means the photons of light captured here left their points of origin almost 300 million years ago. To try to grasp this aspect is humbling to say the least.
- 22. Thank You For Viewing This Presentation! I hope you have found this presentation interesting, informative, and entertaining. The grandeur of the Universe is amazing, humbling, and awe-inspiring. It is said that the heavens declare the glory of God. When I look up, I have to agree whole heartedly. The images here are all taken by myself over the last three years. The times for imaging range from around 30 minutes all the way up to 5 hours. The processing was all done either in Photoshop, PixInsight, or both. When processing and combining all the images, it can litterally take a number of hours to get to the point of having even a halfway decent image. As a side note to this, all the images you have seen from the Hubble had someone take many, many hours to perform the processing. There is a lot of hard work that goes into the processing to bring out the details. It is truly an art. The people who process the images for NASA deserve a lot of credit for what they do. Thank you for viewing!