The Rosette Nebula

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Rosette Nebula

The Rosette Nebula imaged with H-alpha and O-III filters.

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  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: Yes
  • Optical Configuration: 0.72x field flattener & reducer (f/5)
  • Filter(s): H-alpha narrowband (Baader 7-nm); O-III narrowband (Baader 8.5-nm)
  • Camera: ZWO ASI1600-MM Cool
  • Light Frames: 70, 2-min. O-III subs; 50, 2-min. H-alpha subs
  • Calibration Frames: 50 darks, 100 biases, 30 flats per filter
  • Total Exposure Time: 240 min. [(70 + 50) x 2 min.]
  • Gain: 75
  • Sensor Temperature: -10° C
  • Pre-Processing: PixInsight, DeepSkyStacker
  • Color Mapping: Luminance Channel = 80% H-alpha; Red Channel = 100% H-alpha; Green Channel = 40% O-III; Blue Channel = 40% O-III
  • Processing: Photoshop CC
  • Imaging Location: Los Angeles, Calif.

The Rosette Nebula represents one of the finest specimens of a stellar nursery and also makes a perfect deep-sky object to photograph with my newly upgraded imaging system. The new system is now fully automated using Sequence Generator Pro software and includes a Peltier-cooled ZWO ASI1600-MM camera, filter wheel, and auto-focuser. A new computer running Windows 10 helps coordinate the command and control of all hardware. The mount and optics remain the same.

This photo of the Rosette is the product of twelve nights of imaging through H-alpha and O-III narrowband filters under less-than-ideal weather conditions from the light-polluted suburbs of Los Angeles. It is a color-mapped image in which the H-alpha data is mapped to the red and luminance channels and the O-III data is mapped to the green and blue channels. The resulting colors are technically “false,” yet they still create a realistic simulation of natural hues.

The nebula itself consists of a gigantic ball of gas and dust about 130 lightyears wide and 5,000 lightyears from Earth. Intense ultraviolet radiation emitted from a cluster of supergiant stars near its center causes the gas to glow at different colors. The predominant red color comes from the H-alpha emission of hydrogen gas. Winds created by superheated plasma escaping from the supergiant stars have carved out a huge bubble 50 lightyears wide at the nebula’s center. Dark rivers, islands, and clouds of light-absorbing dust also can be seen throughout the nebula.

This vast cosmic accumulation of dust and gas in the constellation Monoceros provides the ideal environment for the formation of new stars and offers an outstanding example of the breathtaking beauty of our universe.

Solar Transit of Mercury

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Click Here for YouTube Video

  • Telescope: Stellarvue SVA130T-IS with Baader solar filter
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: No
  • Optical Configuration: 0.72 x 910 mm (f/5)
  • Digital Zoom: Cropped sensor for 5X magnification. Total magnification = 120X
  • Camera: Canon 60Da
  • Camera Control: Backyard EOS, Planetary Capture
  • Video Loops: 45, 100-frame videos; ~ 20 fps @ 1-min. intervals
  • Shutter Speed: 1/3200 s
  • ISO: 100
  • Calibration: None (no darks, no flats, no biases)
  • Lucky-Imaging Processing: AutoStakkert 2 and RegiStax 6
  • Post-Processing & Frame Alignment: Photoshop CC
  • Video Rendering: iMovie
  • Imaging Location: Los Angeles, Calif.

When the Sun rose in Los Angeles, Calif. on November 11, the 2019 solar transit of Mercury was already well underway. And by the time the Sun cleared my house and the neighbor’s trees, there was less than an hour left to go. Miraculously, the thick marine layer of clouds that had threatened to scrub the photo shoot altogether had also evaporated. Better late than never. It was game on! The next transit of Mercury visible from North America wouldn’t be until 2049!

I had decided to shoot a time-lapse using Lucky Imaging to combat the effects of air turbulence at the high magnification needed to resolve the planet, which was only 10 arcseconds wide during the transit. Ten arcseconds is how wide a soccer ball would appear at a distance of almost 3 miles. Mercury is a tiny planet.

Each image for the time-lapse was first shot as a raw 100-frame AVI video at about 20 fps and a shutter speed of 1/3200 s. I shot 45 raw videos at 1-min. intervals. The sharpest 8 frames from each raw video were then stacked into a single TIFF image with AutoStakkert 2 and sharpened further using Wavelets in Registax 6. Each of the 45 sharpened images was processed and aligned in Photoshop CC. The final time-lapse was rendered from the 45 processed images using iMovie.

Supervisual Photography

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Visual Eclipse
Supervisual Eclipse
Visual Image
Supervisual Image
 

 

One of the greatest challenges of photographing the cosmos — and one of its greatest rewards — is to image objects that are difficult or impossible to see with just our eyes. Most astronomical objects are too dim, too far away, or too bright for us to visualize or photograph easily; and to meet these challenges, astronomers and imaging scientists have developed sophisticated techniques and technologies that extend photography well beyond the normal limits of human vision. This kind of photography I call supervisual photography.

To illustrate the power of supervisual photography, the slider above displays two of my images of the 2017 solar eclipse. The Visual Image closely resembles how the eclipse appeared to the eye during totality, while the Supervisual Image reveals details of the lunar surface and the solar corona that were present during totality but were far too dim to see. It’s important to note that the colors are natural and nothing was added or altered to create this extraordinary photo. Supervisual imaging techniques were applied during imaging and processing to tease out these existing features.

Supervisual imaging methods can also help bring to light deep-sky objects that are too dim to see at all. Such images can take hours or days to shoot before processing them. The resulting photos, however, are well worth the effort, revealing a kaleidoscope of colorful stars and vibrant, neon-like nebulae more breathtaking than anything that could be gleaned by the human eye through even the largest of telescopes.

Supervisual photography captures the jaw-dropping subtleties of the world that exists beyond our vision, a spectacular world that we otherwise could never see to appreciate.

The Lagoon Nebula in H-Alpha

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The Lagoon Nebula

This image of the Lagoon Nebula was shot from Los Angeles with a DSLR in H-alpha light.

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  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: Yes
  • Optical Configuration: 0.72x field flattener & reducer (f/5)
  • Filter: 12-nm narrowband H-alpha
  • Camera: Canon 60Da
  • Light Frames: 32, 5-min. exposures
  • Calibration: 36 darks, 100 biases, 30 flats
  • Exposure Time: 160 min. (32 x 5 min.)
  • ISO: 800
  • Pre-Processing: PixInsight
  • Processing: Photoshop CC
  • Imaging Location: Los Angeles, Calif.

The Lagoon Nebula is one of the finest examples of a stellar nursery and one of only two nebulae visible to the naked eye. Located in Sagittarius, the nebula lies along the intersection between the galactic plane and the plane of our solar system (ecliptic plane), just a few degrees off a direct line of sight to our galactic center (Sgr A*).

The Lagoon is a giant cloud of dust and gas about 100 ly wide, 50 ly high, and about 4,100 ly away. Peppered throughout its expanse are a number of smaller dark features called Bok globules, which astronomers believe to be stars in the making. These “protostars” consist of dense, light-absorbing balls of gas and dust collapsing under their own weight, a process that also created the open cluster of new stars (NGC 6530) that now makes the whole nebula glow. These new stars are only a few million years old, infants on a cosmological time scale.

Ultraviolet light from NGC 6530 and other stars within the nebula causes the hydrogen gas to glow (fluoresce) in the red. A special narrowband filter placed over the camera sensor lets only this red light through and blocks everything else, which allows emission nebulae like the Lagoon to be photographed from light-polluted cities like Los Angeles.

[For Brian — friend, physicist, outdoorsman. You are greatly missed.]

Star-Spangled Eagle

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Star-Spangled Eagle

The Eagle Nebula spreads its wings among a kaleidoscope of glittering stars.

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  • Telescope: Stellarvue SVA130T-IS
  • Mount: Losmandy G-11 with Gemini 2 controller
  • Autoguiding: Yes
  • Optical Configuration: 1x 910 mm (f/7)
  • Camera: Canon 60Da
  • Light Frames: 24, 300-s subframes stacked (120 min.)
  • Calibration: None (no darks, no flats, no biases)
  • Exposure Time(s): 2 h or 120 min. (24 x 5 min.)
  • ISO: 800
  • Pre-processing & Processing: PixInsight
  • Post-Processing: Photoshop CC
  • Imaging Location: Sierra Nevada Mountains (Altitude: 8,600 ft)

When photographing the cosmos, the path to accurate color reproduction often lies in the stars. This image of the Eagle Nebula reveals a broad range of star colors calibrated from their true color temperatures. Faithful depiction of star color ensures the color fidelity of other objects in the image, too.

The deep red color of the Eagle Nebula originates from light emitted by singly ionized hydrogen gas (H-alpha). The vast clouds of gas and dust in nebulae make them effective stellar nurseries, where the stuff of the universe is transformed into gleaming new stars.