Image Gallery: L-500

Sh2-112 by Rod Pommier

Submitted by Chelsea Chin

Sh2-112

Sh2-112 is an emission nebula in Cygnus lying at a distance of 5,600 light-years. It is a blister nebula on the edge of an enormous molecular hydrogen cloud and hydrogen-alpha nebulosity can be seen all around it. It is illuminated by the star BD+45 3216, the bright star near the center of the image. It is a blue supergiant of 30 solar masses. This bright nebula is just a bit north of the well-known North America and Pelican Nebulae, but sadly is rarely imaged.

Image Data:

Telescope: CDK 17

Mount: L500

Camera: SBIG STL 11000M with Baader Planetarium Ha,L,R,G,B filters.

Location: Pommier Observatory, Portland, OR, USA.

Exposures: Ha:L:R:G:B = 315:265:70:70:70 =13 hours, 10 minutes total exposure.

Rod Pommier – Pommier Observatory | Portland, Oregon USA

Rod Pommier Astrophotography

CDK400 System

Submitted by Chelsea Chin

PlaneWave CDK400 System

“The new imaging system in the new Pommier Observatory is a PlaneWave CDK400 system. A CDK 400 system consists of a CDK17 (17-inch) telescope mounted on an L500 mount.

The CDK17 is a fantastic telescope. It is fast, at f/6.8. The optics are truly superb. It produces a completely flat field with stunning clarity and pinpoint stars from corner to corner of my 35 mm CCD chip. It has a fused silica mirror and carbon fiber trusses that resist expansion and contraction and hold sharp focus throughout the night regardless of how much the ambient temperature changes. The CDK17 has many built-in fans that help it reach ambient temperature quickly and blow air across the primary mirror surface to remove the boundary layer of air that can blur images. I added several accessories to the CDK17, like the IRF90 rotator/focuser, the Electronic Focuser Accessory, and the Delta-T Heater dew control system. See those pages for details on them.

The L500 is an equally amazing mount. It is direct drive, so it has no gears and therefore no periodic error and no backlash. Once it builds a pointing model, it precisely centers targets on the CCD chip. It tracks flawlessly for long periods of time. Although I usually still auto-guide when there is a suitable guide star (see page on the IRF90), I can also now image subjects with no available guides star by just letting the L500 run all by itself and I still get perfectly round stars even with long sub-exposures. This enables me to image subjects I never could with my Compustar C14 due to lack of a suitable guide star. The L500 has through-the-mount cabling to prevent cable wrap.”

Check out Rod Pommier’s PlaneWave page, here!

Rod Pommier – Pommier Observatory | Portland, Oregon USA

Rod Pommier Astrophotography

Horsehead Nebula by Rod Pommier

Submitted by Chelsea Chin

B33: The Horsehead Nebula in Orion

Unguided
Taken with a CDK17 on an L-500 Series Mount
Total exposure time over 26 hours

Rod Pommier – Pommier Observatory | Portland, Oregon USA

Rod Pommier Astrophotography

M75 by Rod Pommier

Submitted by Chelsea Chin

M75 in Sagittarius

“Ever wish you could see some of the doubtless numerous deep sky splendors hidden from our view on the far side of our galaxy?

Well, here is one lying in plain sight. M75 is a globular cluster in Sagittarius lying at a distance of 67,500 light-years. This means when we view M75 we are peering past the southern side of the Milky Way’s core and seeing this globular cluster hovering above the far side of our galaxy’s disk. Harlow Shapley and Helen Sawyer classified globular clusters on a scale of I-XII based on how densely their cores were packed. Class I has cores so dense as to be virtually unresolvable, whereas Class XII are so loosely packed as to resemble circular open clusters. M75 is the only Class I globular in the Messier catalog and is notorious for having a core so densely packed that not even the largest amateur instruments can resolve it. However, the CDK 17 resolved its core spectacularly well.

Telescope/Mount: CDK 17 on L500 mount.

Camera: STL 11000M with Baader Planetarium LRGB filters.

Location: Pommier Observatory, Portland, OR, USA.

Exposures: L:R:G:B = 165:60:60:60 minutes = 5hours, 40 minutes total exposure at f/6.8

Rod Pommier – Pommier Observatory | Portland, Oregon USA

Rod Pommier Astrophotography

NGC 6960: The Witch’s Broom Nebula by Rod Pommier

Submitted by Chelsea Chin

NGC 6960: The Witch’s Broom Nebula, in Cygnus

NGC 6960, the Witch’s Broom (also Western Veil or Sharpless 103) Nebula is a remnant from a supernova about 10,000 years ago. Its amazing filamentary structure is due to compression of expanding shells of gas as they meet the resistance of the interstellar medium. That much of what we see as “empty” space is filled with dark dust is evidenced by there being more background stars visible below the nebula, where it has swept space clear of dust, than above it. The bright star, 52 Cygni, is a type K star and a foreground object with no physical association with the nebula but adds to the drama of the image. Please compare this image to my previous image of it taken with my Celestron Compustar C14, shown under Nebulae. The difference in sharpness, clarity, and detail is jaw-dropping.

Telescope & Mount: PlaneWave CDK17 on an L-500 mount

Exposures: Ha:L:R:G:B = 300:245:95:95:95 minutes = 11 hours, 40 minutes total exposure at f/6.8.

Rod Pommier – Pommier Observatory | Portland, Oregon USA

Rod Pommier Astrophotography

M33: The Pinwheel Galaxy by Rod Pommier

Submitted by Chelsea Chin

M33: The Pinwheel Galaxy, in Triangulum

“M33 is one of the closest spiral galaxies lying at a distance of 2,723,000 light-years. Therefore, it appears large and fortunately also presents us with a nearly face-on orientation. As such, it reads like an open book about all the processes one can see going on in a spiral galaxy within this image. Dark nebulae silhouetted against the galaxy condense into stars, many of which are blue supergiants. Once born, they emit intense ultraviolet radiation which ionizes the remaining hydrogen in the cloud, causing it to glow as an emission nebula at the red hydrogen-alpha wavelength of 656.28 nm. They also emit fierce stellar winds that drive that gas away, and the stars become unbound and spread out as an OB association of blue supergiants. But those blue supergiants live fast and die young as supernovae within a few million years. The shockwaves from those supernovae strike the neighboring dark nebulae and cause them to collapse and the process repeats over and over again. As the galaxy rotates over millions of years, these processes trace out curving blue spiral arms ornamented with numerous red emission nebulae.”

Telescope/Mount: PlaneWave CDK17 on L500 Mount

Camera: SBIG STL-11000M with Baader Planetarium filters.

Location: Pommier Observatory, Portland, OR, USA.

Exposures: Ha:L:R:G:B =480:460:110:110:110 minutes = 21 hours, 10 minutes total exposure at f/6.8

Rod Pommier – Pommier Observatory | Portland, Oregon USA

Rod Pommier Astrophotography

NGC 7023 with a CDK500 by Jeff Lovelace

Submitted by Matt Dieterich

NGC 7023 with a CDK500 by Jeff Lovelace.