Nights at Melinda Heights
Astro-imaging Under The City Lights
For a full size image click here.
Distance: 3,300 Light Years
Magnitude: Unknown
Size: 180 Arc-minutes
Age: Approx. 2 million years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 18×600 Bin 1, SII 24×900, Ha 30×900, OIII 16×900
NGC 7822 is a large emission nebula in the constellation Cepheus. It covers about 3 degrees of sky but my image covers just the central part of the nebula. NGC 7822 also contains many different types of objects such as an open star cluster, dark dust lanes, elephant trunk structures, and Bok globules.
The open star cluster is named Berkeley 59 and contains several type O and B stars. These types of stars are very young, large, and hot. Forty two variable stars were also recently cataloged in Berkeley 59 and its surrounding area. Berkeley 59 is about 10 arc-minutes in size and the stars within are 1-5 million years old.
The dark lanes seen in my image are listed in Lynd’s Dark Nebula catalog as LDN 1267, LDN 1268, LDN 1269, LDN 1270, LDN 1271, and LDN 1275. LDN 1267 is about 9 arc-minutes in size. LDN 1268 is about 27 arc-minutes in size. LDN 1269 is about 10 arc-minutes in size. LDN 1270 is about 6 arc-minutes in size. LDN 1271 is about 6 arc-minutes in size. LDN 1275 is about 10 arc-minutes in size.
Elephant trunk structures are areas of colder gas and dust that are cylindrically shaped as a result of the large amounts of ultraviolet radiation emitted from the open star cluster. All of the elephant trunk structures in my image point to the central star cluster Berkeley 59. One elephant trunk structure known as the “Dancing Queen” is actually rotating upon its axes. The “Dancing Queen” trunk is the smaller object to the right of the bigger trunk just below and right of the image center. Elephant trunk structures are also known to be active star forming regions but it often takes IR imaging to see through the dense gas and dust. There are also smaller areas of dense gas and dust in NGC 7822 known as globules. These are smaller concentrations of dust and gas usually spherical or tear dropped in shape.
Below is a LRGB version on NGC 7822 captured from my home in a Bortle 6 zone:
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 18×600 Bin 1, RGB 20×300 Bin 2
For a full size image click here.
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 18×600 Bin 1, RGB 20×300 Bin 2
For a full size image click here.
Distance: 7,100 Light Years
Magnitude: 10
Size: 15 x 8 Arc-minutes
Age: Approx. 300,000 years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 15×600 Bin 1, RGB 15×300 Bin 2
NGC 7635, the Bubble nebula, is an emission nebula in the constellation Cassiopeia. The Bubble nebula is set in a nebulous gas and dust cloud which provides a smooth backdrop for the sharply defined Bubble. The Bubble gets it shape from a massive Wolf-Rayet star named SAO 20575. A Wolf-Rayet star is a very large, hot, and young star that is rapidly shedding outer layers. These stars are larger than 20 solar masses and their temperatures range from 20,000K to over 50,000K. Wolf-Rayet stars eject large amounts of their mass and during this process the expelled layers take various shapes varying from circular to oval. This star is emitting a large amount of ultraviolet radiation travelling at 4 million miles per hour which shapes the ejected gas from the inside while the surrounding exterior gas cloud restricts the expansion giving a sharply defined edge which forms a bubble. SAO 20575 is the brighter star inside of the bubble to the upper left of center. SAO 20575 is 44 times larger than the sun and is a magnitude 8.71 star. It is moving away from the area and this is why it is not in the center of the bubble.
This image was captured with a 1000mm FL telescope and shows the Bubble nebula and the surrounding gas cloud. This image was taken from my house in a Bortle 6 zone.
For a full size image click here.
Distance: 9,500 Light Years
Magnitude: 8.5
Size: 35 Arc-minutes
Age: Approx. 4 million years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 20×600 Bin 1, SII 20×900, Ha 20×900, OIII 20×900
NGC 281, the Pacman nebula, is an open star cluster plus emission nebula in the constellation Cassiopeia. NGC 281 is a desirable object for study because it sits above the galactic plane and this eliminates a lot of interference from galactic dust. It also contains many high mass stars whose ultraviolet radiation is shaping the denser gaseous areas and also helping to provide initiating forces to star formation. The gas and dust that give the Pacman nebula it shape are illuminated by several high mass stars in the open cluster IC 1590. Although IC 1590 contains several hundred stars, it is the massive Type O stars that help shape the dark nebula that forms the mouth of the Pacman feature. Additionally, the ultraviolet radiation from the cluster helps shape the perimeter trunk shaped dust clouds on the left side of my image. These areas are thought to be star forming regions. Also present in the region are several Bok globules in the central area of the nebula. Bok globules are dense areas of dust and gas that are thought to be active star forming regions. It was only recently that near IR images found star formation inside some of these globules. This was previously impossible to determine using visual means because the regions were too dense for optical study.
For a full size image click here.
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 20×600 Bin 1 RGB 20×300 Bin 2
For a full size image click here.
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 20×600 Bin 1 RGB 20×300 Bin 2 Ha 20×900 Bin 1
For a full size image click here.
Distance: 7,200 Light Years
Magnitude: 7.2
Size: 25 Arc-minutes
Age: Approx. 4 million years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 20×600 Bin 1, SII 25×900, Ha 25×900, OIII 25×900
NGC 7380, The Wizard Nebula, is an open cluster surrounded by the emission nebula from which it formed. NGC 7380 is in the constellation Cepheus and contains an eclipsing binary star known as HD 215835. HD 215835 is thought to be the primary illumination source of the nebula and is dead center in my image. It is rather unimposing and doesn’t appear bright enough to be a source star. The cluster and surrounding nebula is part of the much larger Cep OB1 Association located in the Perseus arm of the galaxy. The cluster is not that large at 3-5 arc minutes and is set against a deep star field behind large amounts of dust. This complicates distance calculations and thus the variety of distances found for this object.
Here is an LRGB version:
For a full size image click here.
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 20×600 Bin 1, RGB 20×300 Bin 2
For a full size image click here.
Distance: 2,400 Light Years
Magnitude: 11.5
Size: 170 Arc-minutes
Age: Approx. 1 million years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 20×600 Bin 1, SII 20×900, Ha 20×900, OIII 20×900
The Elephant Trunk nebula, also known as IC 1396 is found in the constellation Cepheus and is about 2,400 light years away. IC 1396 is one of the larger emission nebula taking up about 3 degrees of sky and containing several star forming regions. The most prominent is IC 1396A which is the part that resembles an elephant trunk. IC 1396A is a dense dark cloud of dust that is illuminated by a very bright nearby star that also illuminates the entire nebula. The bright star is HD 206267 and it is a massive Type O star. The radiation and winds from this star are thought to be the force behind the compression of gas and dust creating the star forming regions. Also contributing to illumination of this area is the open star cluster Trumpler 37 which is seen in the foreground of my image. The glowing edges surrounding parts of the dark globules are formed by the excited gas in the Ha region. This presents the bright backdrop for the globule. In the tip of the Elephant Nebula is a circular globule of dust that is open in the middle. Two stars are found here and they are newly formed stars that have cleared a section of the dust cloud as a process of their formation.
Here is an LRGB version:
For a full size image click here.
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 1100
Exposures: L 20×600 Bin 1, RGB 20×300 Bin 2
Here is another SHO version with a different telescope:
For a full size image click here.
Telescope: Televue NP101
Camera: QSI 683
Mount: AP 900
Exposures: SII 19×1200, Ha 22×1200, OIII 16×1200
For a full size image click here.
Distance: 1,400 Light Years
Magnitude: 8.8
Size: 5×7 Arc-minutes
Age: Unknown
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 900
Exposures: L 19×600 Bin 1, RGB 17×300 Bin 2
VdB 152 is a reflection nebula in the constellation Cepheus. It is about 1,400 light years away and is a dim object set in a field of dust known as the Cepheus Flare. Surrounding stars in this area are also discolored as a result of all this dust. BD+69 1231 is the source star that illuminates the reflection nebula and can be seen in the cavity of the nebula. Embedded in this nebula is HH 450, a Herbig-Haro object. Herbig-Haro objects are supersonic outflows from YSO’s that collide with interstellar medium to create compressed lines of material. These show best in images that contain Ha and SII data. It is barely visible in my image but can be seen as a reddish blob to the left of the source illumination star at the dark/reflection nebula boundary. HH 450 is only 33” in length and is only resolved in large telescopes.
Barnard 175 is the cometary-shaped dark dust cloud that tails away from the nebula and is listed as a Bok Globule. A Bok globule is a region of dark cool dust and gas. The densest part of Barnard 175 is approximately 5’ x 7’ in size but the tail extends another 30’. The entire dust complex of Barnard 175 is moving at a different speed than the illuminating source of VdB 152. It was discovered that these two objects are merely passing each other at a speed of 11.7 kms.
The thin red filaments beginning in the upper-left corner of my image and ending at the reflection nebula are the remnants of a supernova explosion. It is cataloged as SNR G110.3 +11.3 and is brightest at the area that intersects VdB 152. This indicates some interaction between the two objects and that their distances from Earth are about the same.
For a full size image click here.
Distance: 3,300 Light Years
Magnitude: 7.2
Size: 12 Arc-minutes
Age: Approx. 1 million years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 900
Exposures: L 41×600 Bin 1, RGB 29×300 Bin 2, Ha 37×600 Bin 1
IC 5146, better known as the Cocoon Nebula, is an open star cluster surrounded by a combination of emission and reflection nebula in the constellation Cygnus. The source of illumination for this nebula is a young type BO star listed as GSC 3608:1446 and is at the center of the nebula. Most sources state an age of 100,000 years for this star. There are several hundred young stars in this cluster that are about 1,000,000 years old. The difference in age would indicate different stages of star development continuing to the present day.
The red regions are emission nebula illuminated primarily by the central star. The bluish regions are reflection nebula caused by visible light reflecting off dust in the area. The darker regions around the nebula and extending away from the nebula are separate dark nebula named Barnard 168. Barnard 168 is the home to many star forming regions. Many of these regions are in various states of development and as of 2008 there were approximately 200 YSO (Young Stellar Objects) candidates. This count was taken from a paper called “The Spitzer Survey of Interstellar Clouds in the Gould Belt. I. IC 5146 Observed with IRAC and MIPS”.
As a side note, this image was taken from my house in an orange zone.
Below is the Luminance Channel only:
Exposures: L 41×600
For a full size image click here.
For a full size image click here.
Distance: 6,000 Light Years
Magnitude: 6.0
Size: 40 Arc-minutes
Age: Approx. 2 Million Years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 900
Exposures: L 16×900 Bin 1, RGB 16×450 Bin 2
NGC 6820 is an emission nebula in the constellation Vulpecula. The most noticeable feature of this nebula is the large elephant trunk structure just below and right of the image center. This large structure gets its shape from the ultraviolet energy emitted from the young star cluster NGC 6823 at the center of my image. The outer regions of this nebula contain many small elephant trunk structures where active star formation is occurring. These stars are very young at 200,000 to 500,000 years which indicates star formation has been triggered after the main star cluster NGC 6823 was formed. This may be due to one of the earlier Type O stars going supernova and the resulting shock wave exciting gas and dust in the outer region of the nebula. There is a small planetary nebula designated as PLN-59.01 to the bottom and right of the image center just below the main elephant trunk structure.
The open star cluster at the center of my image is NGC 6823 and is young at 2 million years. NGC 6823 is also considered the center of the Vulpecula OB1 Association and consists of Type O and B stars which are very young and very hot stars. The high ultraviolet energy from the cluster illuminates the surrounding gas and dust and also shapes the elephant trunk structures. There also Bok globules in the area. These globules are smaller dark clouds of dense gas and dust that are also potential star formation areas. These globules contain hydrogen, helium, carbon, plus silicate and are often responsible for formation of double and multiple star systems. Bart Bok, who first studied these globules in 1940, stated they act like “insect cocoons” as transformational vehicles. He suspected these globules were undergoing gravitational collapse but this was impossible to verify with technology at the time as it was impossible to see inside the dense cloud using images from the visible wavelength. His ideas were later confirmed in 1990 with the use of near infrared images to verify star formation inside.
Below is the luminance image:
Exposures: L 16×900
For a full size image click here.
Exposures: L 12×360 Bin 1, RGB 12×180 Bin 2
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP900
Distance: 5,000 Light Years
Magnitude: 6.0
Size: 11 Arc-minutes
Age: Approx. 1 Million Years
Messier 17 is an emission nebula in the constellation Sagittarius. M17 is also known as the Omega, Swan, or Lobster nebula and lies in the Sagittarius arm of our galaxy. The illumination sources for the nebula are a group of stars behind the bright central gaseous region. These stars are not seen in visual images but are responsible for the unusual whitish color of this region. At first it would appear that any image of this area is over exposed but the whitish color comes from a mix of the reddish emission gas mixed with reflections of bright star light from the surrounding area. The entire nebula is an active star formation region. Surrounding the bright central region is a large emission cloud. This cloud has a very lumpy structure which indicates future star cluster development.
Above and to the right of M17 is IC 4706 and IC 4707 and these are both listed as stars with nebulosity.
This image was captured in one night from my house located in a Bortle 6 zone. I did try to capture this object two years ago with a 65mm refractor and a DSLR but was not really satisfied with the object or the results. I decided to try it again with a larger scope and CCD camera and I am happy I did. I was pleasantly surprised with the results considering the short exposure times. One thing that did surprise me was the lack of detailed information on M17. I searched several sites and most parroted each other. I then tried Google Scholar and found some more info but not as much as I expected for such a common target.
Exposures: L 15×900 Bin 1, Ha+OIII 7×900 Bin 1
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP900
Distance: 5,000 Light Years
Magnitude: 7.4
Size: 18×12 Arc-minutes
Age: 250-400K Years
NGC 6888, the Crescent Nebula, is an emission nebula in the constellation Cygnus. The illuminating source is the Wolf Rayet star WR 136. In general a Wolf Rayet star is a very large hot star that is rapidly shedding mass in the form of ultraviolet radiation. WR 136 is estimated to be 250,000 times brighter than our sun, 15 times more massive, and with a temperature of 70,000 Kelvin. With WR 136, the ejected matter is leaving at a speed of 6.1 million kilometers per hour. This high speed matter hits the ambient dust and gas and gives the Crescent nebula its shape. Part of the surrounding gas and dust is previously ejected material from WR 136 when it was a red giant about 250,000 years ago.
NGC 6888 is a windblown bubble formed by a Wolf-Rayet star that is shedding very hot material in to the surrounding inter stellar medium. It is the gas and dust in the surrounding medium that is compressed in to a thin shell giving the nebula its shape. There are actually two waves of shocked gas, one corresponding to the shocked stellar wind and the other to shocked interstellar gas. The hot interior of this bubble is where the energy is stored and subsequently used for driving the entire structure.
The top image is composed of 900 second Ha and OIII images. The entire area around the nebula is rich in OIII while the interior area is stronger in Ha. This is the first time I tried imaging the Crescent nebula in narrow band and was a bit surprised to see the large OIII ejection area outside of the arc. I did a bit of research on this and a 2014 paper [arXiv:1310.2801v2] said the following:
“The hot gas in NGC 6888 is distributed inside the optical shell delineated by OIII emission. The spatial distribution of the X-ray emission shows enhancements towards the caps and a blowout present in the NW region of NGC 6888. This blowout, not discussed in previous studies, has no Ha counterpart, but an outer skin of OIII is detected. The X-ray emitting gas is, thus, traced by Ha clumps inside the nebular shell and by the blowout. No clear evidence of limb brightening is detected.”
The image below is an LRGB combination captured from my house in an orange zone. The exposures are L 900 seconds bin 1 + RGB 450 seconds bin 2. I was pleasantly surprised that I could get 15 minutes at F7.7 without any difficult gradients.
