June 2023 Stargazing Photos

I saw my first supernova this month. That was the highlight of the night for me. This supernova is the closest one to the Earth in the past nine years. To see the pictures and to get more information, see the Stars section of this blog entry.

In some ways this night of stargazing was typical for a summer night of gazing but there was one big difference. My friend Jeff joined me. It was good to have the company. I enjoyed talking about astronomy with him and discussing all kinds of other things. If anyone else is interested in joining me, just let me know.

We didn’t get started until around 10:30pm since it gets dark so late this time of year. Jeff stuck it out until close to midnight. I hung in there until 2am because I wanted to see Saturn. It is visible at night again but it is pretty late at night (early in the morning?) before it rises. When I finally got home, I could not resist copying the pictures onto my computer so I could view them on my 32” monitor. It was about 5am before I went to sleep. Boy, was I dragging at work the next day!

Spectral Types of Stars

There are lots of stars in my blog entries. In my description of each star, I will often say that “xxx is a type Y” star. “Y” is a single, capital letter that indicates the star’s color and temperature. Stars are classified into 7 main spectral types based on their temperature, with the hottest being O and the coolest being M. The spectral types are as follows:

· O – Hot and Blue

· B – Hot and Blue

· A – Warm and Light Blue

· F – Warm and White or Yellow White

· G – White or Yellow (our sun is Type G)

· K – Cool and Orange or Red

· M – Cool and Red

So our best chance of finding another habitable planet is an earthlike planet around a G type star.

Stars

Let’s start with the supernova and then move on to a few other stars that I chose just because I recognized their names.

SN 2023ixf is a supernova that is so far away (21M LY!) that it just shows up as a dot in my picture of the Pinwheel Galaxy, but I think it is amazing that we can see one star that is 21 million light years away and that I was able to photograph it. Here are two pictures of the Pinwheel Galaxy. The first picture shows the supernova. I took the second picture two years ago. I included it so that you can see that the supernova did not exist back then. You can get more information about the Pinwheel Galaxy in other blog entries. Here is more information about the supernova…

SN 2023ixf is a type II (core collapse) supernova located in the Pinwheel Galaxy (M101). It was first observed on 19 May 2023 by Koichi Itagaki and immediately classified as a type II supernova. The initial magnitude at discovery was 14.9. After discovery, the Zwicky Transient Facility project found an older image of the supernova at magnitude 15.87 two days before discovery. The supernova is about 21 million light-years from Earth and is expected to have left behind either a neutron star or black hole based on current stellar evolution models. The supernova is located near a prominent star forming region, NGC 5461, in an outer spiral arm of the bright galaxy.

By 22 May 2023, SN 2023ixf had brightened to about magnitude 11. It can be seen in telescopes as small as 114 mm (4.5 in) and should remain visually visible with backyard telescopes for a few months. The last supernova this close to Earth was SN 2014J in Messier 82, roughly 12 million light-years from Earth. It appeared over nine years ago. SN 2023ixf started to fade on around 10 June 2023 but should still be visible for months. Before becoming a supernova, the progenitor star is believed to have been a Type M, red supergiant star like Betelgeuse in our own galaxy.

Altair is the brightest star in the constellation of Aquila the Eagle and the twelfth-brightest star in the night sky. Altair is an A-type main-sequence star with an apparent visual magnitude of 0.77 and is one of the vertices of the Summer Triangle asterism; the other two vertices are marked by Deneb (see below) and Vega (see June 2021 blog entry). It is located at a distance of 16.7 light-years (5.1 parsecs) from the Sun.

Antares is the brightest star in the constellation of Scorpius the scorpion. Often referred to as "the heart of the scorpion", Antares is near the center of the constellation. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from an apparent visual magnitude of +0.6 down to +1.6. It is on average the fifteenth-brightest star in the night sky.

Classified as spectral type M, Antares is a red supergiant, a large evolved massive star and one of the largest stars visible to the naked eye. Its exact size remains uncertain, but if placed at the center of the Solar System, it would extend out to somewhere between the orbits of Mars and Jupiter. Its mass is calculated to be around 12 times that of the Sun. Antares appears as a single star when viewed with the naked eye, but it is actually a binary star system, with its two components called α Scorpii A and α Scorpii B. The brighter of the pair is the red supergiant, while the fainter is a hot main sequence star of magnitude 5.5. They have a projected separation of about 529 AU. Antares is located about 170 parsecs (550 ly) from Earth.

Deneb is a first-magnitude star in the constellation of Cygnus. Deneb is one of the vertices of the asterism known as the Summer Triangle and the "head" of the Northern Cross. It is the brightest star in Cygnus the swan and the 19th brightest star in the night sky, with an average apparent magnitude of +1.25. A blue-white supergiant, Deneb rivals Rigel as the most luminous first-magnitude star. However, its distance, and hence luminosity, is poorly known; its luminosity is somewhere between 55,000 and 196,000 times that of the Sun. The traditional name Deneb is derived from the Arabic word for "tail".

Deneb's distance from the Earth is around 802 parsecs (2,620 ly). Deneb is the most luminous first magnitude star, that is, stars with a brighter apparent magnitude than 1.5. Deneb is also the most distant of the 30 brightest stars by a factor of almost 2. Deneb appears to have a diameter of about 200 times that of the Sun; if placed at the center of the Solar System, Deneb would extend out to the orbit of the Earth. It is one of the largest white 'A' spectral type stars known.

Nebulae

This is the second time I have published a picture of the Trifid Nebula. The first time was last July. I decided to look at it again because I wanted to show Jeff one of the most spectacular nebulae in the sky. I included it in this blog entry because the picture is so much better than the last one because I spent twice as long collecting light for the picture. This picture shows that the colors in the nebula are brighter, the nebula is bigger, and you can better see the three lobes that make up the nebula.

The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is in the northwest of Sagittarius in a star-forming region in the Milky Way's Scutum-Centaurus Arm. It was discovered by Charles Messier on June 5, 1764. Its name means 'three-lobe'. The object is an unusual combination of an open cluster of stars, an emission nebula (the relatively dense, reddish-pink portion), a reflection nebula (the mainly NNE blue portion), and a dark nebula (the apparent 'gaps' in the former that cause the trifurcated appearance, also designated Barnard 85). Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers. It is approximately 4,100 light years from the Earth.

The Blue Flash Nebula is the first of several planetary nebulae included in this blog entry. And, as you can see, it is a classic example of a planetary nebula. It is bluish with a white dwarf at its center. Planetary nebulae are created when a star, that is too small to go nova, dies. This is what we expect when our star dies in four or five billion years.

The Blue Flash Nebula, also called NGC 6905, is a small but relatively bright planetary nebula located in the constellation Delphinus the dolphin. The nebula has an apparent magnitude of 10.9 and lies at an approximate distance of 7,500 light years (2,300 parsecs) from Earth. NGC 6905 was discovered by William Herschel in 1784. The central star is 14.0 mag.

The Incredible Shrinking Nebula is a planetary nebula that was given its interesting name because its size depends on how you look at it. Large telescopes that can detect infrared, ultraviolet, etc light can see multiple layers in this nebula that make it appear to be quite “large”. In small telescopes like mine that only see visible light, all you get is the tiny little blue and white nebula you see at the center of this image.

The nebula, also called NGC 6804, is in the constellation Aquila the eagle. NGC 6804 was discovered on 25 August 1791 by William Herschel. The distance to this nebula is unclear. My normal sources of information do not contain anything on this subject.

The Little Gem Nebula is yet another planetary nebula. This nebula intrigued me because it is not spherical but more rectangular; at least, in my picture. It is small and a little off center in this picture but if you zoom in enough, you will see that it is red, white, and blue! That seemed so appropriate because I am writing this entry on July 4th.

The Little Gem Nebula or NGC 6818 is a planetary nebula located in the constellation of Sagittarius. It has magnitude 10 and oval diameter of 15 to 22 arcseconds with a 15th magnitude central star. It was discovered by William Herschel in 1787. NGC 6818 is located in the constellation of Sagittarius (The Archer), roughly 6,000 light-years away from Earth. The glow of the cloud is just over half a light-year across.

When stars like the Sun are near the end of life, they send their outer layers into space to create glowing clouds of gas, a planetary nebula. This ejection of mass is uneven, and planetary nebulae can have complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud. Scientists believe that the stellar wind from the central star propels the outflowing material, forming the elongated shape of NGC 6818. As this stellar wind moves through the slower-moving cloud it creates particularly bright spots in the bubble's outer layers.

The Saturn Nebula (also known as NGC 7009 or Caldwell 55) is a planetary nebula in the constellation Aquarius the water bearer. It was discovered by William Herschel on September 7, 1782 and was one of his earliest discoveries in his sky survey. The nebula was originally a low-mass star that ejected its layers into space, forming the nebula. The central star is now a bright white dwarf star of apparent magnitude 11.5. The Saturn Nebula gets its name from its superficial resemblance to the planet Saturn with its rings nearly edge-on to the observer. Unfortunately, its resemblance to Saturn cannot be discerned with my telescope. The distance of the Saturn Nebula is not known precisely. 2004 estimates the distance to be 5,200 light-years (1.6 kpc). In 1963 O'Dell estimated it to be 3,900 light-years (1.2 kpc), which gives an approximate diameter of 0.5 light years for the object as a whole.

The Western Veil-Nebula is a large, feint (in my image) nebula that stretches from the west north west of the image to the south east of the image. It appears to basically be made up of two bands – one blue and one red – that are stacked on top of each other. The star at the center of the image is 52 Cygni and is not part of the nebula. It just happens to be positioned in a location that makes it appear to be part of the nebula. The Western Veil nebula is not a planetary nebula.

The nebula constitutes the visible portions of the Cygnus Loop, a supernova remnant, many portions of which have acquired their own individual names and catalogue identifiers. The source supernova was a star 20 times more massive than the Sun which exploded between 10,000 and 20,000 years ago. At the time of the explosion, the supernova would have appeared brighter than Venus in the sky, and visible in the daytime. The remnants have since expanded to cover an area of the sky roughly 3 degrees in diameter (about 6 times the diameter, and 36 times the area, of the full Moon). While previous distance estimates have ranged from 1,200 to 5,800 light-years, a recent determination of 2,400 light-years is based on direct astrometric measurements.

The structure is so large that several NGC numbers were assigned to various arcs of the nebula. The Western Veil (also known as Caldwell 34), consisting of NGC 6960 (the "Witch's Broom", Lacework Nebula, "Filamentary Nebula") near the foreground star 52 Cygni.

Galaxies

This is at least the third time I have included the Andromeda Galaxy in a blog entry. I seem to look at Andromeda annually around this time of year. I did it this time because Jeff asked about it. I decided to include the picture because this is the first time I photographed the galaxy and saw such a clear picture of the galaxy where it was obvious what was and was not a part of the galaxy. In older pictures, it was not clear what was and was not in the galaxy. I am not sure what made the difference this time.

The Andromeda Galaxy is a barred spiral galaxy approximately 2.5 million light-years from Earth and the nearest large galaxy to the Milky Way. The galaxy's name stems from the area of Earth's sky in which it appears, the constellation of Andromeda, which itself is named after the Ethiopian (or Phoenician) princess who was the wife of Perseus in Greek mythology.

The number of stars contained in the Andromeda Galaxy is estimated at one trillion or roughly twice the number estimated for the Milky Way. The Milky Way and Andromeda galaxies are expected to collide in around 4-5 billion years, merging to form a giant elliptical galaxy.

NGC 6824 is the small galaxy in the center of this image. To be honest, it looks more like a small nebula and, in fact, galaxies were often mistaken for nebulae in the past. NGC 6824 is a Spiral Galaxy located in the constellation of Cygnus. Its distance from Earth is 172 million light years. That’s why it looks so small in my picture. Its diameter is actually about 76,500 light years. That is around ¾ the size of the Milky Way. It was discovered by William Herschel in the late 1700s.

Star Clusters

M16 is both a nebula and a star cluster. This is one of the two stellar objects I know of that are made up of two different and distinct types of objects. The nebula part of M16 is the Eagle Nebula and contains the Pillars of Creation. M16 is a young open cluster of stars in the constellation Serpens the serpent, discovered by Jean-Philippe de Cheseaux in 1745–46. The cluster associated with the nebula has approximately 8,100 stars, which are mostly concentrated in a gap in the molecular cloud to the north-west of the Pillars. The brightest star (HD 168076) has an apparent magnitude of +8.24, easily visible with good binoculars. This region of active current star formation is about 5,700 light-years distant.

Messier 3 (M3; also NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici the hunting dogs. It was discovered on May 3, 1764, and was the first Messier object to be discovered by Charles Messier himself. Messier originally mistook the object for a nebula without stars. This mistake was corrected after the stars were resolved by William Herschel around 1784. Since then, it has become one of the best-studied globular clusters. Identification of the cluster's unusually large variable star population was begun in 1913 by American astronomer Solon Irving Bailey and new variable members continue to be identified up through 2004.

Many amateur astronomers consider it one of the finest northern globular clusters, following only Messier 13. M3 has an apparent magnitude of 6.2, making it a difficult naked eye target even with dark conditions with averted vision. However, with a moderate-sized telescope, the cluster can be seen as a cloudy smudge even in severely light-polluted skies and can be further defined in darker conditions. The cluster has a bright core with a diameter of about 6 arcminutes and spans a total of double that.

This cluster is one of the largest and brightest and is made up of around 500,000 stars. It is estimated to be 11.4 billion years old. It is centered at 32,600 light-years away from Earth. Messier 3 is quite isolated as it is 31.6 kly above the Galactic plane and roughly 38.8 kly from the center of the Milky Way. You can see this in my picture. There isn’t much that is visible around the cluster.

Messier 5 or M5 (also designated NGC 5904) is, under extremely good conditions, just visible to the naked eye as a faint "star" 0.37 of a degree north-west of star 5 Serpentis. Binoculars and/or small telescopes resolve the object as non-stellar; larger telescopes will show some individual stars, some of which are as bright as apparent magnitude 10.6. M5 was discovered by German astronomer Gottfried Kirch in 1702 when he was observing a comet. Charles Messier noted it in 1764 and—a studier of comets—cast it as one of his nebulae. William Herschel was the first to resolve individual stars in the cluster in 1791, counting roughly 200. Messier 5 is receding from the Solar System at a speed over 50 km/s. M5 is approximately 24,500 light years from us.

This picture is different from the rest. I was trying to find the Jellyfish Nebula but failed. What I found instead was the most densely packed star field I have ever seen outside of a globular cluster. I liked the picture and decided to share it with all of you. I have no details about the image. All I can tell you is that I had my telescope pointed nearly straight south and was looking very close to the horizon.

Planets and Moon

This is the biggest, brightest picture of Saturn I have been able to get so far. It is also the main reason I stayed out so late. I had to wait until the planet rose far enough above the horizon for me to be able to find and photograph it. I was able to get this picture because of a software upgrade that allows my telescope to use its image enhancing functionality on planets and other “near” earth objects. I only wish the rings were in a better position so that we could see more of them.

There was a crescent moon when I went stargazing in June. When I looked at it with my telescope, I noticed that more of the moon was visible than I could see with the naked eye. I decided to focus on the part of the moon that was not lit by the sun. I was able to see this part of the moon because of earth light that was reflected off the moon.