OR: Three nights in Glenn County -- First night -- 10/16/25
Muriel Dulieu Holzer
Three nights in Glenn County
First night – 10/16/2025
A few weeks ago I had the chance to join Steve Gottlieb for three nights of observing in farm country. Some people dream of meditating with the Dalai Lama, or having dinner with the Queen of England. What makes me happiest is observing alongside someone with a lifetime of deep knowledge and experience, far from light pollution, with nothing else to do but focus on the night sky.
When I arrived, Steve’s 24” StarStructure was already set up, standing in the driveway, waiting for dusk. I set up my Orion 10” Dobsonian, my 14.5” Teleport, and my Seestar. The first job of the night was turning off the surrounding lights including two blinking Christmas trees near the road. And then, as the last light faded, the Milky Way arched in its full splendor.
Polaris - The North Star in Ursa Minor
I started by looking at Polaris. Polaris is one of the most famous stars in the sky due to its position almost directly above the Earth’s North rotational axis, which makes it appear nearly stationary in the night sky.
Polaris appears as a double star in most telescopes, with a yellowish primary, Polaris A (magnitude 1.97), and a pale white secondary, Polaris B (magnitude 9.1), separated by 18.6”.
However, Polaris is in fact a triple star system. Polaris A has a close companion, Polaris Ab, which forms a spectroscopic binary. Their orbital motion was first detected in 1929 by Ralph E. Wilson via Doppler shifts, and Polaris Ab was directly imaged with Hubble in 2006 by Nancy Evans and collaborators.
Polaris A is the brightest and nearest Cepheid variable to Earth. Its 3.95-day pulsation period has been changing over time, likely due to internal structural evolution in its stellar envelope. The rhythmic variation is caused by the ionization of helium: when helium atoms lose electrons, they absorb more energy, temporarily trapping heat and forcing the star’s outer layers to expand, until they cool and the process reverses.
Messier 30 - Globular Cluster in Capricornus
M 30, also known as NGC 7099, is a bright globular cluster elongated east to west that contains at least 200,000 stars. It has a dense core and prominent star chains.
Looking at it in the 24”, I can distinctly see two star chains looking like two legs. These two bright star chains extending from the core are internal structural features, not tidal streams. There are some true tidal tails that are composed of fainter stars, extending far beyond the cluster’s visible boundary, but not detectable visually.
These tidal tails are formed as the Milky Way’s gravity gradually strips stars from the cluster’s outer regions.
M 30 is an interesting cluster. It is one of 20 known core-collapsed globular clusters in our galaxy. Over billions of years, the stars in its dense center have gravitationally interacted so much that the core has contracted, leading to countless stellar encounters and mergers.
As a result, as was found in 2009, M 30 contains blue stragglers. Blue stragglers are stars that look younger and bluer than the cluster’s other ancient stars. Two distinct populations of blue stragglers have been found:
One formed through stellar collisions,
The other formed through mass transfer in binaries.
Looking at M30’s origins, it is 13 billion years old. It has likely originated in the dwarf galaxy known as Gaia-Enceladus, which merged with the Milky Way around 10 billion years ago. The evidence that led to this conclusion comes from its orbital motion, which is highly eccentric and retrograde, matching the trajectories of other clusters brought in by that merger. The chemical composition of its stars, very low in heavy elements and with distinct alpha-element ratios, aligns with the stellar populations of Gaia-Enceladus rather than those formed in the Milky Way. The alpha-element ratio being the measure of the abundance of elements made in massive-star supernovae (Magnesium, Calcium, …) compared to iron.
If you, like me, would like to look at the other globular clusters that originated in the Gaia-Enceladus dwarf galaxy, here is the list. I will first list the ones visible from California with a 6” or smaller telescope:
M2 (NGC 7089) in Aquarius,
M75 (NGC 6864) in Sagittarius,
M79 (NGC 1904) in Lepus,
NGC 1851 in Columba,
NGC 2298 in Puppis.
From the Southern sky one can observe:
NGC 2808 in Carina,
NGC 5286 in Centaurus,
NGC 362 in Tucana,
NGC 1261 in Horologium.
In addition to these globular clusters, millions of old metal-poor stars from the Gaia-Enceladus galaxy joined the halo of our Milky Way, they are called Gaia-Enceladus stars. Some of those Gaia-Enceladus stars are part of stellar streams, long ribbons of stars stretched across the sky. Those stellar streams form a whole network called the Gaia-Sausage Debris Field. The number of known stellar streams have exploded recently due to the high-precision astrometric data from the GAIA mission, and currently nearly 100 are known. Some of the best-studied streams are the Gaia-Sausage Stream, Helmi Streams, Sequoia Stream and the Sagittarius Dwarf Stream.
Messier 13 (NGC 6205) - Globular Cluster in Hercules
Just taking a look at M13 in my 8 x 42 Nikon Monarch binoculars, I can barely see it with the clouds. Unlike M 30, M13 is a native Milky Way cluster, formed in situ in the Galaxy’s early halo.
I like to show M13 when I volunteer at public star parties, it is such a showpiece. I like to say that it contains close to half a million stars and everyone is always impressed.
The propeller is not visible with the binoculars, so I will have to look at it again with a telescope. The propeller is a dark three-lobed pattern in M13’s core. I will have to look also for its many red giants and its blue stragglers born mostly from mass transfer in binary systems.
Messier 57 - The Ring Nebula in Lyra
The Ring Nebula is a planetary nebula in Lyra. Once a sunlike star, it exhausted the hydrogen fuel in its core, which led to an expansion of its outer layers and it became a red giant. Further internal instabilities caused its outer atmospheres to be expelled in energetic pulses. The expanding gaseous shell forms the planetary nebula, while the stellar core collapsed to become a white dwarf, brightly illuminating the nebula.
We see the Ring Nebula at an angle of roughly 30 degrees from one pole. Its visible shape is that of a slightly oval ring, brightest along the NE-SW axis. The interior is softly luminous rather than empty. In reality it is a torus with a darker region in the middle where UV radiation is mostly emitted, and a large faint halo around it. The very faint magnitude ~15 white dwarf central star is hard to see and requires ideal conditions and a large telescope.
We tried to look at it in the 24” but unfortunately, due to the clouds, the view was not clear.
NGC 6826 (Caldwell 15) - The Blinking Nebula in Cygnus
The Blinking Nebula is a planetary Nebula. It is so called because it appears to blink in and out depending on how you look at it. The “blinking” effect comes from the bright central star overwhelming the nebula when viewed with direct vision; when using averted vision, the nebula brightens and the star seems to fade.
This blinking effect is an effect of human retina physiology. When you look at the nebula directly, your fovea (center of vision) picks up the bright central star, and the nebula appears to fade. And when you use averted vision, your much more light sensitive peripheral rods detect the nebular glow, and the star seems to dim relative to the nebula. A key ingredient that makes this nebula appear to blink is that its central star has much higher surface brightness per unit area than the nebular shell.
In the 24”, the nebula appears white with averted vision and then when I look directly at it, the central star HD 186924 appears with another near very faint star TYC 3561-1313-1. This faint star however is not part of the nebula, it is a foreground field star. It is an ordinary main sequence star much closer to us that happens to be in the same line of sight.
The central star is a post-AGB core that has finished its red giant phase and is on its way to becoming a white dwarf. It is extremely hot, its spectrum is classified as O6f, and it is currently illuminating the nebula.
Nearby, 5 degrees West, is 16 Cygni, a triple star system in Cygnus. A and B are yellow dwarf sun-like stars that form a wide binary. C is a red dwarf that is a more distant companion. What makes this star system special is that 16 Cygni B hosts a giant exoplanet 16 Cygni Bb. 16 Cygni Bb is a gas giant 2.38 times the mass of Jupiter.
I have looked at the Blinking Nebula a few times before, I still remember looking at it for the first time in an 18” along with others at Henry Coe State Park, what fun everyone was having!
There are other nebulae that appear to blink but this one is the one officially called “The Blinking Nebula” since the effect is most obvious. Other blinking planetaries are:
NGC 2392, the Eskimo/Clown Face Nebula, in Cygnus,
NGC 7662, the Blue Snowball, in Andromeda,
NGC 6572, the Emerald Nebula, in Ophiuchus,
NGC 6210, the Turtle Nebula, in Hercules.
NGC 457 (Caldwell 13) - The Owl Cluster in Cassiopeia
A fun cluster that looks like an owl or E.T. with two stretched arms and two bright stars as eyes. I can see it easily in my 10”.
Depending on the sources, it contains between 140 and 350 stars. And it is located 7922 light years away.
The stars forming the eyes are Phi Cassiopieia and HD 7902.
Phi Cassiopeia is a multiple star system that forms the brighter eye, its primary star is a very luminous yellow F-type supergiant while its second brightest component is a bluish white B-type supergiant.
HD 7902, that forms the other eye, is a bluish white B-type supergiant.
The B-type and F-type refer to the Morgan Keenan (MK) system using the letters O, B, A, F, K and M, a sequence from the hottest (O type) to the coolest (M type).
HD 7902 is likely a member of the NGC 457 cluster based on its Gaia DR3 parallax and proper motion, but the status of Phi Cas is uncertain since its parallax distance is closer than the cluster.
Messier 103 (NGC 581) - Open Cluster in Cassiopeia
Also in Cassiopeia, one can find the open cluster M103. This is a young cluster ~20-30 million years old containing between 77 and 220 stars depending on sources. In my 10”, its brightest stars form a triangle.
Cassiopeia has numerous star-forming regions rich in giant molecular clouds and highly luminous associations of blue stars. One of those areas is located in the Perseus Arm, one of the two major spiral arms of our Galaxy. In the Perseus Arm, some particularly bright OB associations are found including Cas OB8 to which M103 belong. Other members of OB8 are NGC 663, NGC 654, and NGC 659.
Messier 42 (NGC 1976) - Orion Nebula in Orion
Going around randomly with my telescope, I caught a bright nebula. I got really excited about how impressive it was. I did not realize immediately that it was the great Orion nebula that had just risen from the East. I had not seen it since last winter/spring.
We are getting close to midnight. Groups of coyotes are calling back and forth from different locations all around us. This is how they communicate to affirm their territory. Some calls sounded very excited at times, maybe the pack had regrouped and they celebrated one of them returning successfully from a hunt. Coyotes have one of the richest greeting rituals in the canine world.
But going back to the Orion Nebula. The Orion Nebula is a giant cloud of ionized gas and dust where new stars are being born. At the center of it lies the Trapezium Cluster which consists of four main stars, A B C D, two of them, A B, have been identified as eclipsing binaries. The most massive and brightest star of the Trapezium, Theta^1 Orionis C, is an O class main sequence star C1 with a B-type main sequence companion C2 plus a closer fainter companion apparently escaping the system. Theta^1 Orionis C1 is responsible for generating most of the ultraviolet light that is slowly ionizing, and perhaps photoevaporating, the Orion Nebula. The star is making the gas glow and may also be causing it to disperse away from the ionization source.
The Orion Nebula is part of a huge structure called the Orion Molecular Cloud Complex, which stretches over hundreds of light-years. The Orion Molecular Cloud is the closest large star-forming region to Earth. The complex contains a variety of visible and invisible objects including emission nebulae, reflection nebulae, dark nebulae, and open star clusters. The invisible part is made of cold gas and dust hidden from visible light but visible in other wavelengths like infrared.
The evening is reaching its end. It is time for an easy and satisfying treat. Steve attached his enhanced night-vision device with an H-alpha filter to the 24” and I got to look again at the Orion Nebula in all its splendor.
Barnard 33 - The Horsehead Nebula in Orion
Last object of the night, the Horsehead Nebula in the 24” with the electronic eyepiece. I can see a lot of details, simply beautiful.
The Horsehead Nebula is a small dark nebula also located within the Orion Molecular Cloud Complex just south of Alnitak (Zeta Orionis), the easternmost star in Orion’s belt.
It is made primarily of cold hydrogen and helium gas, as well as thick dust blocking the light of stars behind it. It is silhouetted against the glowing emission nebula IC 434. IC 434 is a cloud of ionized hydrogen (H II) being ionized by the very hot and bright O-type star Sigma Orionis. The top ridge of the Horsehead is actively being photoevaporated, ultraviolet light from Sigma Orionis is stripping gas from its surface, producing the bright sculpted edge, and slowly reshaping the nebula over time. Bright spots in the Horsehead Nebula’s base are young stars just in the process of forming.
This concludes a quiet, satisfying evening.
I packed up the Seestar which just finished recording NGC 7331 in Pegasus.
More tomorrow.
Richard Navarrete
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Howard Banich
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Mark Wagner
Steve Gottlieb
You also have to pay tribute to Annie Jump Cannon who invented the scheme and classified over 350,000 stars for the Henry Draper catalogue!
Check out “The Glass Universe” by Dava Sobel
Jamie Dillon, DDK
Rod Brown
Ted Hauter
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