Observatory Images

The following images are from our main 20-inch telescope using one of two cameras, a ZWO 1600MM Pro or Canon EOS 6D DSLR. Many of these images were acquired by observatory visitors, W. Balmer, and M. Prem, and most post-processing was carried out by M. Prem using SIRIL.

Friday, May 26rd, 2023

Color image of M101 with supernova SN2023ixf
M101: This well-known and lovely spiral galaxy is also known as the pinwheel galaxy due to its large spiral disk being oriented almost directly towards Earth. However, this image shows a very special guest that was not visible in this galaxy just a few short weeks before this image was taken: the core collapse supernova SN 2023ixf (appears as a large light-blue blob in the upper-right). While this supernova will fade over time, its host galaxy (known as Messier 101 or M101) is still very interesting due to its large star-forming regions visible scattered throughout its spiral structure. This image is shown in color based on another image of M101 from a few days prior (courtesy of M. Prem), which was used to transfer the colors, using the data taken from the observatory’s monochrome exposure as a luminance layer.
Monochrome image of galaxy M51
M51: Colloquially known as the whirlpool galaxy, M51 is a real treat of the Northern skies, appearing close to the big dipper. Of course, the two interacting galaxies in this image are actually much further away; so far in fact that their light takes over 23 million years to get to us. These are some of the best known interacting galaxies, with the gravitational disruptions causing large tidal streams visible in longer exposure images, and likely contributing to the formation of the well defined spiral arms of the larger galaxy. M51 was the first to be identified as a spiral galaxy (or a spiral nebula as they were known at the time). The smaller, dimmer galaxy IC 4278 is also visible in this image just a little way from M51; see if you can spot it!
Monochrome image of the galaxy M81
M81: Another bright spiral galaxy near the big dipper, this grand design spiral galaxy is in the process of interacting with the nearby galaxy M82. This image highlights the large brightness difference between the very bright core of the galaxy, and the significantly fainter arms, where there wasn’t enough light collected to make them easily stand out from the background. To make the arms visible at all, the stacked image was greatly stretched, with heavy noise reduction applied.
Monochrome image of galaxy M82
M82: A companion galaxy to the spiral galaxy M81, and one of the nearest starburst galaxies, with its starburst thought to have been caused by a previous interaction with M81. A starburst galaxy is one where the rate of star formation is much greater than normal, with M82’s center alone producing around 10 times the new stars that the entire Milky Way galaxy does. This huge amount of star formation causes M82 to be very luminous, with the dust lanes seen in the image silhouetting the brighter background. Not seen in this image, but possible to pick up in longer exposures, are large streams of hydrogen that form a so called superwind which is likely driven by the supernovae which are common in this galaxy.
Monochrome image of the globular cluster M13
M13: A favorite of northern hemisphere astronomers and a target that we have imaged several times before, this large grouping of stars contains the mass of around 600,000 suns packed together far tighter that the local neighborhood of our own solar system. Because of its shape, M13 is known as a globular cluster, as opposed to the more common open star clusters such as the Pleiades. To show the maximum number of stars, this image of M13 was processed to enhance the visibility of faint parts of the cluster while preserving details in its bright core, which combined with the slightly blurred stars to make this image appear different from our other image of M13 shown further down the page.

Sunday, May 21st, 2023 (guest image)

This galaxy is looking different! These images were taken by trained observatory guest Gavin W. (JHU) and Observatory Fellow William B. (JHU). It was processed by Gavin W. using SIRIL. It shows the nearby M101 spiral galaxy, where just this past week a new supernova has erupted. Over the next few weeks, the bright source of light marked “SN 2023ixf” will fade away and disappear completely. Currently it is out shining the combined brightness of all the other stars in its host galaxy! This is one of the nearest supernova to the Earth this decade, an exciting opportunity for astronomers around the world to study these violent stellar-deaths in detail.

Friday, May 19th, 2023

The Ring Nebula (M57) in narrowband H-alpha, O[III] filters. This nebula was generated by a Sun-like star that has finished fusing hydrogen into helium. The nebula is about 7000 years old. The beautiful blue center of the nebula is emission from diffuse oxygen gas left in the wake of the expanding shell of red hydrogen gas, which we isolated at this open house using special filters that cut out a lot of the light pollution from the city.
The Sombrero Galaxy. We only managed to take images in one filter (a Green filter) but even in monochrome, the dramatic dust-lane of this galaxy is impressive. We are viewing this distant galaxy “edge-on” where the dust and gas that orbits within the spiral arms blocks the light from the center of the galaxy.
The Eyes Galaxy. More monochrome green filter images, again showing a beautiful partially edge-on galaxy with spirals of dust along its arms.
A globular cluster, M13, “Great Globular Cluster in Hercules.” This group of stars are more than a hundred times more closely packed together than the stars near our Sun. These stars are almost three times as old as the sun, 12 Billion years old, and this cluster exhibits signs of having been “accreted.” This means that this cluster of stars could have been a much smaller galaxy that the Milky Way gobbled up!

Monday, January 16th, 2023

Comet C/2022 E3 (ZTF), otherwise known as “the Green Comet” or “the Neanderthal Comet” is shown here, about two weeks before its closest approach, having just passed periapsis (when it is closest to the Sun). Images were observed by W. Balmer in Blue, Green, and Red filters using our science camera, and processed by M. Prem using SIRIL. Because it is nearby, the comet has a large apparent motion compared to the background stars, and keeping the telescope fixed on the comet during an imaging sequence results in star trails as seen here.

Tuesday, November 22, 2022

Processed image of Orion Nebula
Orion Nebula. This image combines 31 DSLR exposures with a total integration time of over 15 minutes, processed to bring out detail, calibrate the colors and suppress noise. Glowing gas is reflecting and re-emitting the light of bright young stars, while darker clouds of cool gas and dust frame and partly obscure the view.

Thursday, October 27

Color image of the bubble nebula
Bubble Nebula. A single massive, hot star is responsible for most of the nebula’s emission. Gas expelled from the star’s own “wind” forms the shell; the gas in the shell and in surrounding clouds is excited by light from the star and glows. About an hour’s worth of exposures in narrow band filters sensitive to emission from hydrogen, oxygen, and sulfur gas were combined to form this image. Processing was used to calibrate the colors, bring out details, and suppress background noise.
Crab Nebula. A single exposure, processed to suppress background noise and enhance contrast, reveals details within this iconic celestial object. The nebula itself is the result of a supernova explosion whose light first reached Earth in the year 1054.

Friday, October 21

The following image was obtained with our ZWO 1600MM Pro camera with a narrow-band H-alpha filter.

Monochrome image of eagle nebula through H-alpha filter
Eagle nebula (H-alpha): The eagle nebula seen in this image is an active star-forming region. The energetic emissions from its young stars cause the gas in the nebula to glow in very specific colors, the strongest of which is called H-alpha, from atomic hydrogen gas. When observed through a filter that only lets through this color of light, a significant amount of detail can be seen, from the brightly glowing gas itself as well as the dust clouds that block some of the light. This image was made by stacking 10 exposures to reduce noise and then stretching to show the detail hidden in the shadows.
Image of Saturn and Titan
Saturn and Titan. This image was created by combining short exposures to capture the planet itself with deeper exposures to be able to detect its large moon, Titan.

Friday, October 14

These images are from our Canon EOS 6D with a light pollution filter.

Image of globular cluster M13
M13. This globular cluster is composed of stars that are about 11.65 billion years old, nearly 3 times older than the Solar System! Observatory open house attendees took 5 images with a total exposure time of 11 minutes which were aligned and combined to produce the image pictured here.
Image of planetary nebula M27
M27. This target, called Dumbbell Nebula or the Apple Core Nebula, is a cloud of gas and dust expelled by a dying, Sun-like star. At its center is the remnant of the progenitor star, called a “white dwarf.” It is only about 10,000 years old, a very short time in astronomy! A certain young attendee took one 3 minute image of M27, which we post-processed using “photometric color calibration” to match the colors in the image to catalogue colors from research images, and then applied a brightness stretch and de-noising filter.
Image of planetary nebula M57
M57. The Ring Nebula was a favorite of our open house attendees, who took about 20 minutes’ worth of images of this nebula. Similar to M27, this nebula was generated by a Sun-like star that has finished fusing hydrogen into helium. The nebula is about 7000 years old. The beautiful blue center of the nebula is emission from diffuse oxygen gas left in the wake of the expanding shell of red hydrogen gas. We combined, smoothed, and then stretched the images to produce the final picture.