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  3. The "Cat's Paw" Nebula can be found in Scorpius. NGC 6334 is relatively nearby, astronomically speaking - about 5.5 kly away from us - and, at 50 ly across, it is intrinsically large. Visually, it is covers a section of the sky that is approximately 40' x 23', which is slightly larger than the full moon. It is another of those popular objects for astrophotographers, and for good reasons; it's big, bright, and has an interesting shape. In a wider view of the object, there is no mistaking why it was given its name. With this image, however, I chose a much closer framing of the object to show the stunning amount of nebulosity and activity taking place inside it. This is an incredibly productive stellar nursery; many of its stars are only a few million years old - mere babies! These hot new stars help provide the radiation that makes this emission nebula glow so brightly. At the other end of the stellar life cycle, information given out by the ESO suggests that the burst 'bubble' in the top of the image may be due to a star that is either at the end of its allotted time or has already exploded. The Paw is reddish when photographed without a filter, but the deep red hue of this image is due primarily to the addition of H-alpha light to the mix. As I have mentioned elsewhere in this blog, H-alpha light is perceived by human beings as a very deep red (656.28 nm) part of the visible spectrum. When added to a 'normal' light image, it not only provides artistic interest, but, also, information about the amount and structure of ionised hydrogen gas in a region. Photo stuff:Date: 06 August 2019R.A.: 17h 20m 14sDec. -36° 02' 39"Canon 60Da on Meade RCX400 f/8 16" with 0.70 focal reducer22 subs @ 300s ea., normal light; 23 subs @ 300s ea., Ha light; ISO 1600, all subs
  4. Gary

    IC 4603

    This is not the prettiest of astronomical objects, but I like it for the sheer amount of action that it implies - interstellar dust and hydrogen gas are blowing every which way, and star formation is occurring at quite a clip due to an ancient supernova having taken place nearby. IC 4603 - the central nebulosity in this image - can be found near Antares, but just inside the borders of the constellation Ophiuchus. The dust is illuminated by the light of SAO 184376, a bright (Mag. 7.6), pre-main sequence, B-type star, which gives us that distinctive blue of a reflection nebula. Photo stuff:Date: 06 & 07 July 2019R.A.: 16h 25m 22sDec. -24° 18' 41"Canon 60Da on Meade RCX400 f/8 16" with 0.70 focal reducer55 subs @ 300s ea.; ISO 1600
  5. I published a wide-field photo of Messier 20 (about 4.1 kly, in Sagittarius) back in June, which prompted me to go after a proper 'head and shoulders' shot - with a twist, as this time I combined luminance and narrowband light. "Narrowband" is a term used by astrophotographers to denote the use of one or more filters to gather image data from very narrow slices of the spectrum. In this image, those filters were hydrogen-alpha (looking through it, an intense red), hydrogen-beta (dark blue), and oxygen-III (cyan/green-ish), bolstered by the luminance data. Besides making for some very striking photos, narrowband filters can give a better sense of the structure and composition of a nebula. Be warned, though: data acquisition to get a fair image can be a lengthy and challenging task, and, despite the technical aspects, the final post-processing is very much more an art than a science. Photo stuff:Date: 07 and 12 July, 2019R.A.: 18h 10m 04.0sDec. -21° 48' 21.1"Canon 60Da on Meade RCX400 f/8 16"; Astronomic .7 focal reducerLuminance: 17 subs @ 300s ea.; ISO 1600 Narrowband: 12 subs @ 300s ea. filter; ISO 1600
  6. Gary

    NGC 5367 and CG12

    This is a rather complex pair of objects in the constellation Centaurus. The blue reflection nebula is NGC 5367, which is mainly notable for being illuminated by the binary star h4636. While the nebula is quite pretty, the more interesting object, for me and for the professional astronomy community, is the brownish cloud that envelopes and slightly obscures NGC 5367. This is the cometary globule CG12, which extends somewhat further off the left side of this image. Cometary globules get their name from their appearance, which vaguely resembles a rather poorly formed comet. Most of these types of globules hang about near the galactic plane but CG12 is a bit unusual in this respect. Gopinathan et al. (2004) have suggested that it sits about 200 pc (~650 light years) above the plane at a distance of 550 pc (~1800 light years) from us. Photo stuff:Date: 28 June 2019; 03 July 2019R.A.: 13h 58m 00.5sDec. -40° 03' 07.2"Canon 60Da on Meade RCX400 f/8 16" with 0.70 focal reducer36 subs @ 300s ea.; ISO 1600
  7. Gary

    IC 4605

    A welcome run of clear nights recently allowed me to lose yet more sleep and get some imaging done. This is the result of one of those runs. IC 4605 is a beautiful reflection nebula that is lit up by the bright (magnitude 4.8) blue, main sequence star, 22 Scorpii, which lies about 413 light years away from us. Although the star is visible from a reasonably dark sky site, long exposures with a camera are needed before the tenuous dust clouds that envelope it can be seen. This nebula is part of the much larger and very colourful Rho Ophiuchi Nebula complex. I have an image of that somewhere that I'll try to dig out and post here when I get a chance. Photo stuff:Date: 28 June 2019R.A.: 16h 30m 14.4sDec. -25° 07' 08.0"Canon 60Da on Meade RCX400 f/8 16" with 0.70 focal reducer24 subs @ 300s ea.; ISO 1600
  8. As I was making my way through my past images, I came across one from 2017 that - rather oddly - I had not yet fully processed. This is a wide field photo of the Trifid Nebula (Messier 20). It is a perennial favourite of astrophotographers, and a relatively easy target for beginners to learn data gathering and post-processing. M20 is a stellar nursery located about five degrees west from Lambda Sagittarii and two degrees northwest of Messier 8 (Lagoon Nebula). It has the unusual characteristic of having several distinct components: reflection (blue), emission (pink), and dark (the 'lanes') nebulae, along with a prominent star cluster (NGC 6514). Photo stuff: Date: 02 May 2017 R.A.: 18h 00m 19.1s Dec. -22° 48' 20.5" Tamron 500mm f/8 catadioptric lens mounted on Canon 6D 22 subs @ 120s ea.; ISO 800
  9. Gary

    The Moon & Jupiter

    This one was unplanned. The sky cleared, I stepped out into the backyard, and there was Jupiter about 3 degrees from a just-past-full moon. I grabbed a few shots and created this composite. The composite was necessary to show all the objects, of course, because exposing for the moon completely dims Jupiter and loses its Galilean moons, while exposing for Jupiter makes the moon look like the lens is staring at the sun. In the end, I processed three separate frames (Moon, Jupiter, and the Galilean moons) as they appeared through the viewfinder. Date: May 21, 2019 (about 01:00) R.A. (approx.): 17h 22m 10s Dec. (approx.): -21° 07' 50" Photo stuff: Exposure times: Moon = 1/640s and Jupiter = 1/4s; ISO 400; Canon 6D; Tamron 500mm f/8 catadioptric lens
  10. Gary

    NGC 2736

    This is another of those "challenging" objects I unwisely decide to tackle occasionally. This one is worth it, though, I think. Herschel's Ray, also known as the Pencil Nebula, is a beautiful swipe of blue and pink shock waves in the constellation Vela. At 3/4 of a light year in size, it is a reasonably sized object in its own right. However, it is just a tiny portion of the truly gigantic Vela Supernova. That "remnant" is what was left after a very large star cataclysmically exploded as a Type II supernova about 11,000 years ago. The force of this destruction, in turn, created a swath of delicate nebulae across at least 8 degrees (ye gods!) of the southern sky. At its distance (815 ly), this equates to an object about 100 ly across. The hues in NGC 2736 are due to two different types of nebulae: pink indicates an emission nebula, while blue is the light scattered off a reflection nebula. When we view this object, we are actually looking at the ripples of a sheet of gas almost edge-on. Dates: 04 February, 2019R.A.: 09h 03m 23.9sDec.: -45° 30' 56.9"Photo stuff: (subs) 131 frames @ 180s ea.; ISO 800; Canon 60Da on the Meade RCX400 16" f/8; Astronomics 0.7 focal reducer
  11. I know, I know - not the prettiest name for a such an interesting galaxy, but I didn't come up with it. NGC 2442 is an example of a peculiar, barred spiral galaxy. In this case, its peculiarity is most likely due to gravitational tides when it interacted with another galaxy at some point in its history; possibly the smaller one (PGC 21456) visible to its right. Besides leaving it with an odd shape, the interaction would have started a burst of star formation evident in its arms. The Meathook, which is approximately 56 Mly away, can be found in the constellation Volans. Although not the brightest of galaxies (sorry, Meathook), it can be seen in relatively small telescopes if you are a practiced observer and under good, dark skies. Dates: 01 March, 2019; 05 March, 2019R.A.: 06h 37m 08.9sDec.: -69° 34" 16.2"Photo stuff: (subs) 37 frames @ 180s + 34 frames @ 300s ea.; ISO 800; Canon 60Da on the Meade RCX400 16" f/8; Astronomics 0.7 focal reducer
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