August 2023 Stargazing Photos

Hello everyone! I am starting this blog entry on October 23rd. I have finally gotten around to posting the photos I took last August. I will try to post my pictures quicker in the future…

I would like to start by mentioning a great gift I received from my neighbor Marilyn. She gave me a book called The Backyard Astronomer’s Guide by Terrence Dickinson and Alan Dyer. It is considered the definitive guide for amateur astronomers like me. It has a lot of great information in it about the best ways to view the sky with your eyes, binoculars, and telescopes. It was written before computerized telescopes like my eVScope became readily available, so it contains many tips and tricks on how to find your way around the night sky. And much, much more. I have found it to be very useful. Thanks Marilyn!

You have all heard me complain about the cold weather I have had to endure during winter stargazing nights. Well, that certainly wasn’t a problem when I went out in the middle of August. In fact, I started sweating as I lugged my gear to my viewing spot. Not pleasant but so much better than freezing my butt off. And, it was worth it. I am very pleased with the images I was able to collect in August.

Throughout my blog entries, you have seen many objects referred to by their “NGC” number, so I decided it is finally time to tell you what the NGC is…

The New General Catalogue of Nebulae and Clusters of Stars (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the Index Catalogues (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use.

The NGC expanded and consolidated the cataloguing work of William and Caroline Herschel, and John Herschel's General Catalogue of Nebulae and Clusters of Stars. Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The original NGC contained multiple errors, but there have been many updates and revisions over the past 50 years.

Planets

I know I said this in my last entry but here is the biggest, brightest picture of Saturn that I have ever taken. This picture is so good because Saturn was just a couple of weeks from opposition when I took the picture.

When a planet is in opposition, it means that the planet is located on the opposite side of the Earth from the Sun. This happens when the planet, Earth, and Sun are aligned in a straight line, with Earth in the middle. During opposition, a planet is closest to Earth and appears brighter than usual. This is because the planet is fully illuminated by the Sun and reflects more sunlight back to Earth.

As with so much in space (and on Earth), the appearance of Saturn’s rings from Earth is cyclical. In 2017, the north side of the rings opened up most widely (27 degrees), as seen from Earth. That’s the most open this side of the rings has been since 1988.

In 2023, the angle is down to 8.1 degrees but it’s still very easy to see the expanse of the rings as we look at the planet’s northern hemisphere. The rings span 44.2 arcseconds with the planet disk spanning 19 arcseconds.

By 2025, the rings will appear edge-on as seen from Earth. Because the rings are so thin, Saturn may look as if it has no rings at all! After that, we’ll begin to see the south side of Saturn’s rings, which will gradually increase to a maximum inclination of 27 degrees by May 2032.

My pictures of Jupiter are continuing to get better too. In August, Jupiter was still a couple of months from opposition, but it is getting better.

You might want to review some of the earlier pictures of these planets that I have posted to see how they have changed over time.

Here is my first picture of Neptune in about a year. It is too far away to see much detail, but the bluish tint can be seen on this photo.

Star Clusters

Star clusters are one of the most common types of celestial objects visible from Earth. That’s one of the reasons why I photograph so many of them. And, just to remind you…

Star clusters are groups of stars held together by mutual gravitational attraction. There are two main types of star clusters:

· Open clusters, which are more loosely clustered groups of stars, generally containing

fewer than a few hundred members, and are often very young.

· Globular clusters, which are tight groups of hundreds to millions of old stars which are

gravitationally bound.

Star clusters form from large regions of gas and dust known as molecular clouds.

Some clusters share a name with a nebula that is in or near the same region of the sky. One of these is the Butterfly Cluster. [I did not take the time to be able to see the nebula in this photo.] The Butterfly Cluster (cataloged as Messier 6 or M6, and as NGC 6405) is an open cluster of stars in the southern constellation of Scorpius. Its name derives from the vague resemblance of its shape to a butterfly. [I don’t see it.]

The first astronomer to record the Butterfly Cluster's existence was Giovanni Battista Hodierna in 1654. However, Robert Burnham Jr. has proposed that the 2nd century astronomer Ptolemy may have seen it with the naked eye while observing its neighbor the Ptolemy Cluster (M7). Credit for the discovery is usually given to Jean-Philippe Loys de Chéseaux in 1746. Charles Messier observed the cluster on May 23, 1764 and added it to his Messier Catalog.

Estimates of the Butterfly Cluster's distance have varied over the years. Wu et al. (2009) found a distance estimate of 1,590 light-years, giving it a spatial dimension of some 12 light years. Modern measurements show its total visual brightness to be magnitude 4.2 so it can be visible to the naked eye. The cluster is estimated to be 94.2 million years old. 120 stars, ranging down to visual magnitude 15.1, have been identified as most likely cluster members. Most of the bright stars in this cluster are hot, blue B-type stars but the brightest member is a K-type orange giant star, BM Scorpii, which contrasts sharply with its blue neighbors in photographs.

Messier 103 (also known as M103, or NGC 581) is an open cluster where a few hundred, mainly very faint, stars figure in Cassiopeia. It was discovered in 1781 by Charles Messier's friend and collaborator Pierre Méchain. It is located between 8,000 to 9,500 light-years from the Solar System and ranging over about 15 light years. It holds about 40 certain-member stars, two of which have magnitudes 10.5, and a 10.8 red giant, which is the brightest within the cluster. The cluster may have 172 stars if including those down to 50% probability of a gravitational tie. M103 is about 22 million years old.

Messier 12 or M 12 (also designated NGC 6218) is a globular cluster in the constellation of Ophiuchus. It was discovered by the French astronomer Charles Messier on May 30, 1764, who described it as a "nebula without stars". In dark conditions this cluster can be faintly seen with a pair of binoculars. Resolving the stellar components requires a telescope with an aperture of 8 in (20 cm) or greater. [Or a light accumulating scope like my 4.5 incher!] In a 10 in (25 cm) scope, the granular core shows a diameter of 3′ (arcminutes) surrounded by a 10′ halo of stars.

M12 is about 16,400 light-years (5,000 parsecs) from Earth and has a spatial diameter of about 75 light-years. The brightest stars of M12 are of 12th magnitude. M10 and M12 are only a few thousand light-years away from each other. M12 is rather loosely packed for a globular and was once thought to be a tightly concentrated open cluster.

Messier 92 (also known as M92, M 92, or NGC 6341) is a globular cluster of stars in the northern constellation of Hercules. It was discovered by Johann Elert Bode on December 27, 1777, then published in the Berliner Astronomisches Jahrbuch during 1779. It was inadvertently rediscovered by Charles Messier on March 18, 1781, and added as the 92nd entry in his catalogue. William Herschel first resolved individual stars in 1783.

It is one of the brighter of its sort in apparent magnitude in the northern hemisphere and in its absolute magnitude in the galaxy, but it is often overlooked by amateur astronomers due to angular proximity to bright cluster Messier 13, about 20% closer. Though when compared to M13, M92 is only slightly less bright, but about 1/3 less extended. It is visible to the naked eye under very good viewing conditions. M92 is also one of the galaxy's oldest clusters. It is about 26,700 light-years away from the Solar System. Its true diameter is 109 ly, and may have a mass corresponding to 330,000 suns.

I just watched an episode of Nova called "New Eye on the Universe". It focused on the James Webb Space Telescope. M92 was used to calibrate the JWST because this cluster has been intensively studied over the past 100 years so astronomers know exactly what kind of readings the JWST should get when looking at M92.

NGC 7380 is a young open cluster of stars in the northern circumpolar constellation of Cepheus, discovered by Caroline Herschel in 1787. [It is also known as the Wizard Cluster.] The surrounding emission nebula is known colloquially as the Wizard Nebula, which spans an angle of 25′. [You can see some of the nebula in the lower right portion on my picture. It looks like a reddish haze.] German-born astronomer William Herschel included his sister's discovery in his catalog, and labelled it H VIII.77. The NGC 7380 complex is located at a distance of approximately 8.5 kilolight-years from the Sun, in the Perseus Arm of the Milky Way. The cluster spans ~20 light-years (6 pc) with an elongated shape and an extended tail. Age estimates range from 4 to 11.9 million years. At the center of the cluster lies DH Cephei, a close, binary system consisting of two massive O-type stars.

NGC 6811 is an open cluster in the constellation of Cygnus, near the constellation of Lyra. It has an angular size half that of the full Moon and includes about 1000 stars of roughly similar magnitude. It has also been called "The Hole in the Cluster" because of its dark center.

NGC 6811 lies far away from the galactic plane, a feature it shares with many other old open clusters. It is 1107 ± 90 parsecs (about 3,285 light years) distant and approximately 4-6 parsecs (14–20 light years) in diameter, with a total luminosity of 2100 suns. Approximately 1.00 ± 0.17 billion years old, the cluster probably contained some 6000 stars at birth, but gravitational interactions and stellar evolution have since reduced the number substantially. A recent study reported 377 confirmed member stars, with spectral types ranging from mid-F to early K. It is "a rich cluster with equally bright stars with no noticeable central concentration". The stars do, however, have an unusual (if not concentrated) distribution, with an apparent stellar corona surrounding the core, leaving the impression of a hole.

NGC 6811 was first observed by John Herschel in 1829 and was added to his General Catalogue of Nebulae and Clusters in 1864. It appears as a hazy patch in 10x binoculars, but it is best seen at around 70x with a moderate-aperture telescope. It has been described by amateur astronomers as a "smoke ring of stars" or "a jeweled mask a woman might wear at a masquerade ball".

NGC 7789 (also known as Caroline's Rose or the) is an open cluster in Cassiopeia that was discovered by Caroline Herschel in 1783. Her brother William Herschel included it in his catalog as H VI.30. This cluster is also known as the "White Rose" Cluster or "Caroline's Rose" Cluster because when seen visually, the loops of stars and dark lanes look like the swirling pattern of rose petals as seen from above. It is 7,600 light years from us.

The ”rose” takes up the center third of my picture but has been magnified too much for its “rose-ness” to be immediately obvious. Here is another picture from Wikipedia that has much less magnification so it is easier to see the white rose. Again, look at the center of the picture.

Nebulae

The Cocoon Nebula (IC 5146) is located in a crowded field of stars spanning approximately 2 degrees. This interesting emission/reflection nebula resides within the constellation Cygnus, which rises high overhead to stargazers in mid-northern latitudes. This nebula is almost 15 light-years wide and located 4,000 light-years away. IC 5146 is a compact star-forming region, with a long trail of obscuring interstellar dust clouds. This image illustrates how the bright star near the center of the Cocoon Nebula is powering the intense nebular glow, and clearing out a cavity in the areas of star-forming dust and gas.

This nebula is comprised of a molecular cloud, which is a giant condensation of dust and molecular gas. All stars are born in molecular clouds, and typically stand out in red, glowing hydrogen gas as seen in the Cocoon Nebula. The Cocoon Nebula is considered to be one of many “stellar nurseries“, as this is where new stars are being born.

I decided it was time to get a better picture of the Ring Nebula that I last included in my December 2022 blog entry. I spent 2.5 times longer creating this picture. The result is a brighter and sharper image.

The Ring Nebula (M57) is a planetary nebula in the northern constellation of Lyra. (Lyra was often represented on star maps as a vulture or an eagle carrying a lyre.) Fans of the Big Bang Theory may recognize this nebula as the one seen in Leonard’s and Sheldon’s apartment. The nebula can be found southwest of the star Vega and is 2,567 light years away.

The Snowball Nebula or NGC 6781 is a planetary nebula located in the equatorial constellation of Aquila, about 2.5° east-northeast of the 5th magnitude star 19 Aquilae. It was discovered July 30, 1788 by the Anglo-German astronomer William Herschel. The nebula lies at a distance of 1,500 ly from the Sun. It has a visual magnitude of 11.4 and spans an angular size of 1.9 × 1.8 arcminutes.

The bipolar dust shell of this nebula is believed to be barrel-shaped and is being viewed from nearly pole-on. The magnitude 16.88 central star of the planetary nebula is a white dwarf. It has an M-type co-moving companion at a projected separation of under 5,000 AU.

Galaxies

NGC 3079 is a barred spiral galaxy about 50 million light-years away and located in the constellation Ursa Major. A prominent feature of this galaxy is the "bubble" forming in the very center of it.

NGC 5907 (also known as Knife Edge Galaxy or Splinter Galaxy) is a spiral galaxy located approximately 50 million light years from Earth in the constellation Draco the Dragon. William Herschel discovered the galaxy in 1788.

Stars

Alioth, also known as Epsilon Ursae Majoris, is the brightest star in the constellation of Ursa Major, and the brightest of the seven stars of the Big Dipper. It also shares the 31st place as the brightest star in the night sky with Alnitak.

Alioth is classified as a white or blue-white, giant or subgiant star. Alioth is located at 82.6 light-years / 25.3 parsecs away from our sun in the constellation of Ursa Major. The star’s apparent magnitude is 1.77 while its absolute magnitude is -0.2. Alioth is a variable star. Alioth is more massive than our sun, having around 2.91 solar masses. It is also much hotter than our sun. Alioth is around 102 times brighter than our sun, yet the star is younger, having an estimated age of 300 million years. Alioth has been used throughout history as a star for celestial navigation in the maritime trade.

Rasalhague, Alpha Ophiuchi (α Oph), is a binary star system located in the constellation Ophiuchus. It marks the head of the celestial Serpent Bearer. With an apparent magnitude of 2.07, it is the brightest point of light in the constellation. It lies at a distance of 48.6 light years from Earth.

The Alpha Ophiuchi system consists of Alpha Ophiuchi A, a white subgiant star and Alpha Ophiuchi B, an orange main sequence star. The stars orbit each other with a period of 3,148.4 days (8.62 years). The primary component, formally named Rasalhague, has a mass about 2.4 times that of the Sun. The star’s estimated age is 770 million years.

Rasalhague is one of the 58 bright stars that have a special status in the field of celestial navigation. It is one of two navigational stars in Ophiuchus. The other one is the fainter Sabik, Eta Ophiuchi. The two stars belong to a group of 13 equatorial navigational stars of the western hemisphere.

Sadalsuud, designated as Beta Aquarii, is the brightest star in the zodiacal constellation of Aquarius. It has an apparent magnitude of 2.87, slightly surpassing Sadalmelik / Alpha Aquarii, which is at magnitude 2.94. Beta Aquarii bears the traditional name Sadalsuud, which comes from an Arabic expression “sa’d al-su’ud” – which means “luck of lucks”.

Sadalsuud is located at around 540 light-years / 165 parsecs away from our Solar System. Sadalsuud appears as a single star to the naked eye, however, it has two optical companions. They are much fainter, distant, smaller, and don’t appear to be gravitationally bound with Sadalsuud. Sadalsuud is a yellow supergiant star. Sadalsuud has 4.97 solar masses, and 47.88 solar radii, thus it is around 100 times bigger than our Sun. This star is also very bright, being 2,046 times brighter than our Sun.

This star is 110 million years old. It is much younger than our Sun.

The zodiacal constellation of Aquarius is among the oldest in the sky. It was listed among the first 48 Greek constellations in Ptolemy’s 2nd century Almagest. Aquarius is now among the 88 modern constellations, being the 10th largest in the sky, stretching for around 980 square degrees. The best time to observe Sadalsuud, the other stars, and deep-sky objects in Aquarius, is during the month of October.