M78, LDN 1622, and a piece of Barnard's Loop

Top right is a structure composed of a batch of dark nebulae clustered around the reflection nebula Messier 78 (M78, NGC 2068), about 1,350 lightyears away, and bottom left is LDN1622, the "Boogeyman Nebula" about 500 lightyears away. And the wide ribbon running between them, mostly ionized hydrogen and interstellar dust, is part of "Barnard's Loop", which runs around the Alnitak side of the constellation Orion. 

Imaging Notes: 49 x 300-second subs taken with the ZWO ASI071MC color camera (cooled to 0°C, gain 0) and the William Optics Redcat 51 apochromatic refractor (250mm FL, f/4.9), Sky-Watcher EQ6-R Pro mount, ZWO ASIAir Plus astro controller. I shot 94 sub-expsures at 5-minutes each, starting around 7pm and running through the night to about 4am, but ended up tossing almost half of them, stacking the best 49.

Posted December 20, 2023

M45, the Pleiades

The Pleiades, M45, also called the Seven Sisters, is a very bright and distinct open star cluster in Taurus, surrounded by the reflection nebula NGC 1432 (most of that pale blue interstellar dust and cloudiness). The Seven Sisters are very hot blue stars about 444 lightyears away. Where I am in the northern hemisphere, around 43° latitude, the Pleiades rises in the night sky in October, peaks in January at almost 50° in the southern sky, before sinking below the horizon by the end of March—and then we don't see it in the night sky again until late autumn.

To the ancient Greeks, over 2,500 years ago, the rising of the Pleiades marked the start of shipping season, when sailing the Mediterranean was a bit less dangerous. Like a lot of ancient mariners, Ancient Greek sailors and navigators relied on astronavigation, using the stars to determine their precise position on the surface of the earth. An ancient Athenian ship could leave the Piraeus and sail directly out to sea, then head west, toward Syracuse, tracking the stars the whole way to determine their course. They would also be keeping track of the Pleiades' position in the sky each night, and use that to determine if they should pick up cargo and make the return trip or pick up some local coastal work through the summer and return to Athens in the fall.  

Imaging Notes: 71 x 5-minute sub-exposures stacked in PixInsight. ZWO ASI071MC color camera cooled to 0°C, Gain 0, Antlia V-Series Luminance/UV-IR Cut filter, William Optics RedCat 51 Apochromatic Refractor 250mm FL, f/4.9, Sky-Watcher EQ6-R Pro mount, ZWO ASIAir Plus astro controller.

Posted December 16, 2023

M42 Test with the new RedCat 51 and the ASI071 color camera

Well, that worked pretty well for an 88% waxing moon with the ZWO ASI071MC color camera. The near-full moon and Jupiter at opposition were just far enough away to make this set up work--plus a lot of 5-minute exposures. That band of red at the top left is the tail end of the ridge of hydrogen that runs behind the Horsehead Nebula (B33). Imaging notes: 63 x 300-second subs, no filters with the ZWO ASI071 color camera cooled to 0C, William Optics RedCat 51 Apo refractor, Sky-Watcher EQ6-R Pro mount. The Orion Nebula (M42), Running Man Nebula (Sh2-279), De Mairan's Nebula (NGC 1982,M43), and surrounding nebulosity. 

Posted November 24, 2023

Astro Session November 18

Flaming Star Nebula (IC 405, SH 2-229, Caldwell 31) and the Tadpole Nebula (IC 410) in the constellation Auriga, along with the two bright areas of emission toward the bottom, the "Spider and Fly", IC 417 and NGC 1931. 42 x 300-second subs in hydrogen-alpha.

IC 2177, Seagull Nebula region in Ha:

Posted November 19, 2023

Imaging Session 2023-11-16

The Heart Nebula on the right (IC 1805, Sharpless 2-190) and Soul Nebula, left, (Westerhout 5 with the star cluster IC 1848) in Hydrogen-alpha. These two make up a massive star-forming complex in Cassiopeia about 7500 lightyears away in the Perseus Arm of our Galaxy. The bright emission nebula on the far right is the Fishhead Nebula (NGC 896, IC 1795). The small circular cloud, middle top, is another emission nebula Sh2-198, much further away, around 18,000 lightyears (still, well within the galaxy). The bright cluster of stars in the core of the Heart Nebula is Melotte 15.

Imaging Notes: 51 x 5-minute exposures stacked in PI, ZWO ASI2600MM-Pro monochrome  camera cooled to -10C, 3nm Antlia Pro Hydrogen-alpha filter, William Optics SpaceCat 51 apo refractor, Sky-Watcher EQ6-R Pro mount. Shot from my backyard in coastal New Hampshire, bortle 4-ish.

Orion Core: two-panel mosaic of Orion's Belt, the Horsehead Nebula, and M42, the Orion Nebula.

Posted November 17, 2023

Astro Session 2023-11-11

Orion’s Belt or the Three Sisters: next time you see that familiar line of three bright stars, the “Orion’s Belt” asterism at the center of the constellation Orion, imagine the backdrop of ionized hydrogen and all the other surrounding stuff you can’t see with your eyes, the bright nebulae, the dark structures of dust and molecular gasses, vast stellar nurseries with violent new stars forming out of trillions of kilometers of hydrogen clouds. There’s so much going on behind these three stars. The center of the Belt, Alnilam, is a single massive star, a supergiant that’s 375,000 times brighter than our star. Alnitak is a triple star system, and Mintaka is a binary star, with the two stars orbiting each other every 5.7 days.

Imaging Notes: 60 x 5-minute exposures stacked in PI, ZWO ASI2600MM-Pro monochrome  camera cooled to -10C, 3nm Antlia Pro Hydrogen-alpha filter, William Optics SpaceCat 51 apo refractor, Sky-Watcher EQ6-R Pro mount. Shot from my backyard in coastal New Hampshire, bortle 4-ish. 

Our giant neighboring galaxy, Andromeda (M31) in HaRGB. I captured this data last night, waiting for Orion to rise above 30°. Imaging Notes: 30 x 120-second subs in RGB, 30 x 180-second subs in Ha stacked in PI, ZWO ASI2600MM-Pro monochrome  camera cooled to -10C, Antlia Pro filters, William Optics SpaceCat 51 apo refractor, Sky-Watcher EQ6-R Pro mount. Shot from my backyard in coastal New Hampshire, bortle 4-ish.

Posted November 12, 2023

Sunday Night Imaging Run

I spent most of the night capturing OIII (Oxygen 3) and SII (Sulfur 2) data in the IC1396 region in Cepheus, enough to combine with last week's Ha (Hydrogen-alpha) data to create a SHO color image, mapping sulfur to red, hydrogen to green, and oxygen to blue in RGB. I've balanced the RGB intensity, but left green for Ha a bit higher. Hydrogen is the most abundant element in the universe—by a very wide margin, and without balancing the Ha, OIII, SII channel values, most nebulae would be overwhelmingly green. That said, I do like to keep more hydrogen green in my images, making them a bit truer to the emission values of most deep sky objects.

I spent the last three hours of the night capturing Ha data of NGC 1499, the California Nebula, about a thousand lightyears away in the constellation Perseus. 

astrophotography NGC 1499

Posted October 10, 2023

Pretty good for an 80% moon

From last night’s narrowband imaging run: IC 1396 is a bright HII region over 2000 lightyears away in Cepheus, illuminated and ionized by the very energetic multi-star system HD 206267 (that’s the brightest star in the center of the image). The massive star, top left-ish, is a red supergiant, “the Garnet Star”, μ Cephei (mu Cephei). Mu Cephei is almost 100,000 times brighter than our star, the Sun, and it's over a 1000 times larger. Imaging notes: 61 x 300-second exposures stacked in PixInsight, camera: ZWO ASI2600MM-Pro cooled to -10C, Antlia 3nm Hydrogen-alpha filter. Even with an 80% waning moon, last night turned out well.

Posted October 3, 2023