Glorious Star Factories Shine In Astounding Amateur Shots

We often publish photos from professional observatories, but it’s important to note that amateurs can also do a great job taking pictures of the sky with modest equipment and photo processing software.

On Universe Today’s Flickr pool, we’re proud to showcase the work of all the fans of the cosmos. Included here are some of the best shots of galaxies and nebulas that we’ve seen uploaded to the site in recent days.

The Milky Way shines over Termas de Chillán in this photo taken by "Miss Andrea" on Flickr.
The Milky Way shines over Termas de Chillán in this photo taken by “Miss Andrea” on Flickr.
The center of the Heart Nebula captured by David Wills on Flickr.
The center of the Heart Nebula captured by David Wills on Flickr.
Simeis 147, the "Spaghetti Nebula", shines in hydrogen alpha in this image captured by Rick Stevenson on Flickr.
Simeis 147, the “Spaghetti Nebula”, shines in hydrogen alpha in this image captured by Rick Stevenson on Flickr.
The Tarantula Nebula imaged in Ha, OIII and SII by Alan Tough on Flickr.
The Tarantula Nebula imaged in Ha, OIII and SII by Alan Tough on Flickr.

 

Ghostly Cat’s Eye Nebula Shines In Space Telescope Calibration Image

Here’s a glimpse of how a telescope gets ready for its main mission. The European Space Agency’s Gaia telescope is in the middle of a commissioning phase before mapping out the locations of stars and other objects in the Milky Way. While the nominal mission is not to take pictures, it is through these images that controllers can verify that the telescope is tuned properly to do its work.

What you’re seeing is data from the Gaia camera’s “sky-mapper strips” that are actually intensity maps rendered in black and white, ESA explained. You can see in the picture above that the shot on the left is a bit blurry, while the one on the right looks a bit sharper. That’s because controllers better calibrated the charged coupled devices to the spacecraft’s spin rate, ESA said.

Lucky for us, ESA is sharing those images so we can see the process in action. This set of pictures below follows on from a calibration image of the Large Magellanic Cloud that was released last week. More details are available at ESA and also in this Dec. 19 Universe Today story.

A calibration image of M94 taken by Gaia, a Milky Way-mapping telescope, in early 2014. The gap is due to the image appearing on two separate CCDs. Credit: ESA/DPAC/Airbus DS
A calibration image of M94 taken by Gaia, a Milky Way-mapping telescope, in early 2014. The gap is due to the image appearing on two separate CCDs. Credit: ESA/DPAC/Airbus DS
Writes the European Space Agency in February 2014: "This is a rotated Gaia image section (left; extracted from the cluster image of NGC 2516 above), compared to a Digital Sky Survey image taken from the ground (right)." Credit: ESA/DPAC/Airbus DS/DSS
Writes the European Space Agency in February 2014: “This is a rotated Gaia image section (left; extracted from the cluster image of NGC 2516 above), compared to a Digital Sky Survey image taken from the ground (right).” Credit: ESA/DPAC/Airbus DS/DSS

What Glows Green In Space?

While a quest for green beer in space would be difficult, we’re happy to report there are other ways you can celebrate Saint Patrick’s Day while looking at the night sky. Just check out the nebulae and aurorae in these pictures!

A word of caution, these pictures are taken by cameras that expose light for a very long time, sometimes using different filters, to bring out the colors. A nebula, for example, seen with our own eyes does not look quite as stunning.

The picture above shows the Wreath Nebula, which apparently is filled with warm dust bits that are about the same composition as smog.

RCW 120. Credit: NASA/JPL-Caltech
RCW 120. Credit: NASA/JPL-Caltech

Here’s a picture of a “Green Ring” Nebula; the NASA press release is worth a read for the hilarious Green Lantern references. But besides the science fiction, there is some neat science in action here: “The green color represents infrared light coming from tiny dust grains called polycyclic aromatic hydrocarbons,” NASA writes. “These small grains have been destroyed inside the bubble. The red color inside the ring shows slightly larger, hotter dust grains, heated by the massive stars.”

A portion of the Lagoon nebula imaged by the Gemini South telescope with the Gemini Multi-Object Spectrograph. Credit: Julia I. Arias and Rodolfo H. Barbá Departamento de Física, Universidad de La Serena (Chile), and ICATE-CONICET (Argentina).
A portion of the Lagoon nebula imaged by the Gemini South telescope with the Gemini Multi-Object Spectrograph. Credit: Julia I. Arias and Rodolfo H. Barbá Departamento de Física, Universidad de La Serena (Chile), and ICATE-CONICET (Argentina).

You can even see hints of green in the Lagoon Nebula picture above. Using a filter that picks up green (sulfur) emission, the astronomers ferreted out a bit of emerald.

An October 2012 picture from Jason Arhns in Alaska, which he calls a “ghost flame.” Credit: Jason Arhns
An October 2012 picture from Jason Arhns in Alaska, which he calls a “ghost flame.” Credit: Jason Arhns

If you live far enough north or south, you occasionally get to see aurorae dancing across the sky. These events, sometimes known as the Northern Lights or Southern Lights, occur due to interactions between the sun’s particles and the Earth’s upper atmosphere. We had some green stunners in October 2012 after a solar flare pushed a bunch of these particles in Earth’s direction. Most of the light you see in auroras comes from oxygen atoms being “excited” from the interaction with the sun’s particles; green occurs at higher altitudes, and red at lower ones.

Light curve of different stars.
Light curve of different stars.

One object that can’t glow green in space, however, is a star. Stellar colors depend on the surface of the star. Blue stars, the hottest ones, are at about 12,000 Kelvin and red stars, the coolest ones, are less than 3,500 Kelvin. (The sun is about in the middle, at 6,800 Kelvin, as it emits white light.)

As Universe Today publisher Fraser Cain pointed out in a past post, the only way a green star could be possible is if the light curve peaks at green. That doesn’t work, however: “If you make the star hotter, it just gets bluer,” he wrote. “And if you make a star cooler, it just becomes orange and then redder. There’s no way to have a light curve that makes a star look green.” Check out more details here.