A fleeting moment in (astronomical) time

Image: ESO 1902a Credit: ESO
The faint, ephemeral glow emanating from the planetary nebula ESO 577-24 persists for only a short time  — around 10,000 years, a blink of an eye in astronomical terms. ESO’s Very Large Telescope captured this shell of glowing ionized gas — the last breath of the dying star whose simmering remains are visible at the heart of this image. As the gaseous shell of this planetary nebula expands and grows dimmer, it will slowly disappear from sight. An object much closer to home is also visible in this image — an asteroid wandering across the field of view has left a faint track below and to the left of the central star. And in the far distance behind the nebula a glittering host of background galaxies can be seen. Credit: ESO

 

An evanescent shell of glowing gas spreading into space — the planetary nebula ESO 577-24 —  dominates this image. This planetary nebula is the remains of a dead giant star that has thrown off its outer layers, leaving behind a small, intensely hot dwarf star. This diminished remnant will gradually cool and fade, living out its days as the mere ghost of a once-vast red giant star.

Red giants are stars at the end of their lives that have exhausted the hydrogen fuel in their cores and begun to contract under the crushing grip of gravity. As a red giant shrinks, the immense pressure reignites the core of the star, causing it to throw its outer layers into the void as a powerful stellar wind. The dying star’s incandescent core emits ultraviolet radiation intense enough to ionize these ejected layers and cause them to shine. The result is what we see as a planetary nebula — a final, fleeting testament to an ancient star at the end of its life.

This dazzling planetary nebula was discovered as part of the National Geographic Society  — Palomar Observatory Sky Survey in the 1950s, and was recorded in the Abell Catalogue of Planetary Nebulae in 1966. At around 1400 light years from Earth, the ghostly glow of ESO 577-24 is only visible through a powerful telescope. As the dwarf star cools, the nebula will continue to expand into space, slowly fading from view.

This image of ESO 577-24 was created as part of the ESO Cosmic Gems Programme, an initiative that produces images of interesting, intriguing, or visually attractive objects using ESO telescopes for the purposes of education and public outreach. The program makes use of telescope time that cannot be used for scientific observations; nevertheless, the data collected are made available to astronomers through the ESO Science Archive.

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The Beautiful “Gulf of Mexico”

Photo: four panel mosaic of an area called the "Gulf of Mexico" which is part of a much larger area of nebulosity called The North American Nebula or NGC7000. Image by Joe Golias
“Gulf of Mexico” Region of NGC7000

CAA member and local astronomy business owner Joe Golias has shared a new image with us that, well, all we can say about it is that it’s astounding! Here’s Joe’s description of how he produced his photograph of a region of NGC7000…

This was by far the most challenging imaging project I have attempted to date. It represents a four-panel mosaic of an area called the “Gulf of Mexico” which is part of a much larger area of nebulosity called The North American Nebula or NGC7000. This object is located in the constellation of Cygnus. This four-panel mosaic was acquired over a period of three weeks. Total exposure time was 56 hours. We’ve had a long stretch of clear skies here in Ohio which made this image possible.

Object: Gulf of Mexico | Telescope: Takahashi TOA 150 refractor | Telescope Mount: Losmandy G-11 | Camera: SBIG STT8300 with self-guiding filter wheel | Exposure: 56 hours of combined narrowband HA, OIII & SII filters | Location: “Astrozap Ridge,” Medina, Ohio. | Image processing: MaxIm DL, Images Plus, PixInsight, Photoshop CS6

The Beautiful “Elephant Trunk”

IC 1396 - The "Elephant Trunk" Nebula in Cepheus, by Joe Golias
IC 1396 – The “Elephant Trunk” Nebula in Cepheus

by Joe Golias

We were fortunate enough to have clear skies this past weekend and I managed to do some narrowband imaging from my back yard in Granger, Ohio. I’d like to share with everyone one of my latest CCD images taken of the Elephant trunk nebula IC 1396 located in the constellation of Cepheus. I often wonder why I bother traveling great distances to dark sky sites like Texas and Florida when I can get results like this from my back yard in Ohio!

Imaging details: Telescope: Takahashi TOA 150 Refractor. Camera: SBIG ST8300M with self-guiding filter wheel. Mount: Losmandy: G-11. Exposure times in narrowband: 4 hours SII filter with 20-min. sub exposures, 4 hours OIII filter with 20-min. sub exposures, 4 hours HA filter with 20-min. sub exposures. Location: Granger, Ohio. Processed in MaxIm DL, Images Plus, Pixinsight, and Photoshop. Final RGB combination was converted using the Hubble color palette, HST.

CAA Member Joe Golias is (obviously) an expert astro-imager and is owner of Astrozap, a Cleveland-area company that produces astronomy accessories.