April 15, 2015 - Galaxies, a Globular Cluster and the Dumbbell

The weather over Westchester County has not been especially conducive to astronomy these last several weeks. Too many cloudy nights, or clear nights dominated by a too-bright moon. Still, this is the best time to look beyond the Milky Way and see the galaxies that are scattered like gems so very far away.

M13

Actually, we'll start with something much closer to home. The famed Hercules Globular Cluster, a great ball composed of several hundred thousand stars packed close together. Located about 22,000 light years away, M13 is part of the Milky Way and is easily visible through binoculars or small telescopes. The cluster can sometimes be detected as a fuzzy patch with the naked eye -- about a third of the way between the stars Eta and Zeta Herculis, if viewed from a very dark location away from city lights.

The English polymath Edmond Halley first noted the cluster in 1714; French comet-hunter Charles Messier added it to his famous list of fuzzy objects in 1764.

This image was composed with 15, 120-second sub-exposures for a total exposure time of 30 minutes. It was taken through the 8" Schmidt-Cassegrain at f/10. All images in this post were captured with the Starshoot Pro camera.

M27 -- The Dumbbell Nebula

One more local attraction before we leave the Milky Way. Though this nebula is definitely a resident of the summer sky -- appearing in the constellation Vulpecula -- it had risen high enough at the end of my last imaging session to get a preview.

Born when an aging star blew off its outer layers, M27 is a planetary nebula. The star that gave it birth survives as a much-shrunken white dwarf at its center. The nebula is thought to be less than 15,000 years old and is located more than 1,300 light years away. It is easily visible in binoculars or a small telescopes as a faint greenish-white cloud having the apparent shape of a dumbbell or hourglass -- hence it's common name.

This image was taken through the 8" Schmidt-Cassegrain at f/10 and comprised of 24, 120-second subs, for a total exposure time of 48 minutes.

M88

And now we move outside of the Milky Way ... indeed, a very long way outside it. M88 is a spiral galaxy that appears in the constellation Coma Berenices. Part of the Virgo Cluster of galaxies, it is estimated to be about 55 million light years distant. The galaxy is seen at about a 64-degree angle.

I didn't get as many subs as I wanted for this image, so I will have to return to M88 again before summer arrives. 23, 120-second subs taken through the 8" Schmidt-Cassegrain at f/10 were combined to create this 46-minute exposure.

M101 

This is a large spiral galaxy, seen face-on, that appears in the constellation Ursa Major. With a disk roughly 170,000 light years in diameter, M101 is home to more than 100 billion stars. It is located around 20 million light years away and is sometimes called the Pinwheel Galaxy. It is faintly visible in small and medium-sized telescopes under dark skies.

This image is composed from 55, 120-second subs taken through the 8" Schmidt-Cassegrain at f/10 over two nights earlier this month. Total exposure time on this image is just under 2 hours, but at least another hour will be needed to draw out detail in the spiral arms.

M109

Also appearing in Ursa Major, M109 is a barred-spiral galaxy. The galaxy is estimated to be between 60 and 84 million light years away and is part of a group of about 50 galaxies.

40, 120-second subs taken through the 8" Schmidt-Cassegrain at f/10 were combined to create this 80-minute exposure.

March 15, 2015 - Spring Spirals

Spring is in the air and the night sky is filled with galaxies. 

M51 - The Whirlpool Galaxy

First noted by French astronomer Charles Messier in 1773, this "nebula's" spiral structure wouldn't be detected until the Earl of Rosse observed it in 1845. Today, we know that this "spiral nebula" is in fact a vast conglomeration of billions of stars, gas and dust, a galaxy, located roughly 23 million light years distant in the spring constellation Canes Venatici.

This is undoubtedly the best image of M51 that I have taken so far, and it is the first I've shot at f/10 though the 8" Schmidt-Cassegrain. The image is composed of 53, 120-second sub-exposures, taken on the night of March 12, for a total exposure time of 106 minutes. It is my intention to acquire several more hours of exposure time for M51 over the coming weeks.

M65, M66 & NGC3628

Three galaxies in the same field of view. M65, which appears at the top of the image is about 35 million light years away, while M66, on the right edge of the image, is about 36 million light years away. NGC3628, located about 35 million light years away, is at the lower left edge of the image. All three -- known as the Leo Triplet -- are spiral galaxies and appear in the constellation Leo.

M65 and M66 were discovered by Charles Messier around 1780, while NGC3628 was first noted by William Herschel in 1784.

This image comprises 23, 120-second sub-exposures taken through the 8" Schmidt-Cassegrain at f/6.3 on the night of March 11, for a total exposure time of 46 minutes.

NGC2903

First noted by William Herschel in 1784, NGC2903 is a relatively bright barred-spiral galaxy located about 30 million light years away, appearing in the constellation of Leo.

The above image was composed from 25, 120-second images, taken through the 8" Schmidt-Cassegrain at f/10 on the night of March 12.

M3

This ancient globular cluster is thought to contain about half a million stars. It's age has been estimated at eight billion years. Charles Messier first noted it in 1764. Almost 34,000 light years away, it appears in the constellation Canes Venatici. 

This image is composed of 17, 60-second sub-exposures taken through the 8" Schmidt-Cassegrain at f/6.3 on March 11.

A Parting Shot at the Horsehead

IC 434 - The Horsehead Nebula

Though I had already imaged this object in November and early December, I took a final series of exposures over the final days of December, because, well, who can resist getting a better image of the famous object? The resulting image -- taken with the 6" Newtonian using the SSP camera -- is probably the best image of the nebula I have yet taken and certainly the best of 2014.

The above image is composed of 28, 200-second sub-exposures and 31, 180-second sub-exposures, for a total exposure time of just over three hours.

With this I saw goodbye to the Orion and the winter sky for this year, and turn my attention toward Leo, Ursa Major and the other spring constellations -- and their myriad galaxies and globular clusters -- that are now rising earlier and earlier in the eastern night sky.