M101 – The Pinwheel Galaxy – is a face-on spiral galaxy 21 million light-years away from Earth in the constellation Ursa Major (Big Dipper). Located just west of the last star in the handle.
M101 is a large galaxy containing approx 1 trillion stars, with a diameter of 170,000 light-years. By comparison, the Milky Way has a diameter of between 100,000 and 120,000 light-years.
M101 has a high population of H II regions, many of which are very large and bright. H II regions usually accompany the enormous clouds of high density molecular hydrogen gas contracting under their own gravitational force where stars form. H II regions are ionized by large numbers of extremely bright and hot young stars; those in M101 are capable of creating hot superbubbles. In a 1990 study, 1,264 H II regions were cataloged in the galaxy. Three are prominent enough to receive New General Catalogue numbers—NGC 5461, NGC 5462, and NGC 5471.
There are at least 4 different galaxies resolved within this image. M101 is the largest and closest. NGC5474 is at the lower left. NGC5477 is above the bottom arm of M101 and appears equally distant between the two yellow stars. NGC5473 is at the far left of the image in the middle.
Image acquisition via APT using a SW Esprit120ED, ASI2600MC Pro, OPT L-Pro filter, & EQ6r Pro mount from my backyard in the hills of western NC.
Messier 104, also known as the Sombrero Galaxy, is an edge-on spiral galaxy in the Virgo constellation. It’s 28 million light-years away, 50,000 light-years across, and has a mass of 800 billion suns. It’s the brightest galaxy within a 32.6 million light-year radius of the Milky Way.
The Sombrero Galaxy is named for its resemblance to a Mexican hat, with a broad rim and high top. It’s best seen with small telescopes during the months of March, April, and May.
The galaxy has a supermassive black hole at its center. Hubble observations also reveal that the Sombrero Galaxy has nearly 2,000 globular clusters, which is 10 times more than in our galaxy. French astronomer Pierre Méchain discovered the Sombrero Galaxy in 1781, but it wasn’t included in Messier’s original catalog.
Stars The Sombrero Galaxy contains several hundred billion stars, about 100 times as many stars as there are people today on Earth.
Globular clusters The Sombrero Galaxy has an estimated 2,000 globular clusters, 10 times as many as orbit our Milky Way galaxy.
Dust lane The Sombrero Galaxy’s most striking feature is the dust lane that crosses in front of the bulge of the galaxy. This dust lane is actually a symmetrical ring that encloses the bulge of the galaxy.
Sh2-274, also known as the Medusa Nebula or Abell 21, is a planetary nebula in the constellation Gemini.
It is located 1,500 light-years away and has an estimated diameter of 4 light-years. The nebula is around 8,800 years old and was discovered in 1955 by UCLA astronomer George O. Abell
A planetary nebula is a region of cosmic gas and dust formed from the cast-off outer layers of a dying star. Despite their name, planetary nebulae have nothing to do with planets.
When stars with an intermediate mass (greater than 80% of the Sun’s mass, but less than eight times its mass) die, they expand to form red giants. The dying star will continue to expel gas, whilst simultaneously the remaining core of the star contracts and temporarily begins to radiate energy again. This energy causes the expelled gas to ionise, meaning that the atoms and molecules in the gas become charged and begin to emit light. The cast-off glowing gas is known as a planetary nebula. Therefore, planetary nebulae are classified as emission nebulae, and are entirely unrelated to planets.
The misnomer came about because of a historical misclassification. 250 years ago, astronomers thought they were looking at gas planets when they observed the colourful spectacle of planetary nebulae through their less powerful telescopes. Planetary nebulae only last for about 20 000 years, making them a very short-lived part of the stellar life cycle.
This is a wide field view of the Virgo Cluster of galaxies. There are 14 galaxies solved and annotated. A brief description of several galaxies is provided. An annotated version is available in the astrobin link – click the image.
NGC 4638 is a lenticular galaxy in the Virgo constellation with a magnitude of 12.1. It’s about 50 million light-years away and is a member of the Virgo Cluster. Astronomer William Herschel discovered NGC 4638 on March 15, 1784. NGC 4638 is very bright and moderately large, with an edge-on disk and a diffuse, boxy halo. The halo has a shallow surface brightness gradient, which is characteristic of a large spheroidal galaxy.
NGC 4637 is a lenticular galaxy in the Virgo constellation with a magnitude of 12.711. It was first discovered by R.J. Mitchell on March 1, 1854, and is located near the celestial equator.
M 59 – Messier 59 (M59), also known as NGC 4621, is an elliptical galaxy in the constellation Virgo, about 50 million light-years away from Earth. It is part of the Virgo Cluster, which contains about 2,000 galaxies, and is one of the largest elliptical galaxies in the cluster. M59 has an absolute magnitude of -22.82 and a magnitude of 9.6. It has an estimated mass of 250 billion suns, which is greater than the Milky Way, but only a quarter of that of its nearby companion M-60.
M 60 – Messier 60 (M60), also known as NGC 4649, is an elliptical galaxy located in the Virgo constellation, about 54 million light-years from Earth. It’s about half the size of the Milky Way, but contains an estimated 400 billion stars, which could be four times the amount in our galaxy. M60 is about 60,000 light-years across and has an apparent magnitude of 9.8. M60 contains one of the most massive black holes known, with a mass of about 3.4 billion times the Sun’s mass. This black hole makes up 15 percent of the galaxy’s mass, which is too big to have formed inside a dwarf galaxy. The black hole is not producing any big outbursts of energy, and unlike the black holes in many other galaxies, it is not beaming out strong “jets” of charged particles.
NGC 4660 – NGC 4660 is an elliptical galaxy in the Virgo constellation, about 63 million light-years away. It has a magnitude of 12.16 and is part of the Virgo Cluster. Astronomer William Herschel discovered NGC 4660 on March 15, 1784. NGC 4660 contains 205 globular clusters, which is typical for its size and brightness. Globular clusters often contain hundreds of thousands of old stars
NGC 4647 – NGC 4647 is a faint, intermediate spiral galaxy in the Virgo constellation, about 63 million light-years away. NGC 4647 is about two-thirds the size of Messier 60, the third brightest galaxy in the Virgo cluster. The two galaxies have overlapping optical disks, suggesting they may be interacting. However, photographic images don’t show any evidence of gravitational interaction between the two galaxies. Studies with the Hubble Space Telescope show that a tidal interaction may have begun. NGC 4647 is part of a pair of galaxies known as Arp 116, along with Messier 60, which is an elliptical galaxy. NGC 4647 is much lower in mass than Messier 60, and is roughly the size of the Milky Way.
NGC 4607 – NGC 4607 is a barred spiral galaxy in the Virgo constellation, about 56 million light-years away. It has a magnitude of 13.75 and is located near the celestial equator. Astronomer R. J. Mitchell discovered NGC 4607 on April 24, 1854.
NGC 4606 – NGC 4606 is a barred spiral galaxy in the Virgo constellation, about 55 million light-years away. It has a magnitude of 12.67, an apparent diameter of 2.8 arc minutes, and is located near the celestial equator. Because of this, it is at least partially visible from both hemispheres at certain times of the year.
IC 3704 – IC 3704 is a barred spiral galaxy in the Virgo constellation, near the celestial equator.
Sh2-302, also known as the Snowman Nebula, is a red emission nebula located in the constellation Puppis, about 5,800 light years away. It’s part of the Gum Nebula, which occupies the lower southern skies in winter. The nebula has a visual diameter of 15 arc minutes and is located near the boundary between Puppis and Canis Major.
Sh2-302 is one of many objects in a catalog compiled by astronomer Stewart Sharpless to identify areas of interstellar ionized hydrogen, or HII regions.
I captured this photograph Feb 18, 2024 and March 13, 2024 using a Skywatcher Esprit 120ED telescope at a fl of 840mm and a ZWO ASI071MC Pro astrophotography camera with an Antlia quad-band light pollution filter. These are mounted on a Skywatcher EQ6r Pro German Equitorial Mount. The image acquisition software that controls everything is APT (Astro Photography Tool). Total exposure of 4.4 hrs. 75 exposures were integrated and processed using Pixinsight.
Sometimes you are pleasantly surprised by what comes from these reflection nebula. Other times not so much. This image was centered on VdB 27 (catalogued also as Ced 31) – a small reflection nebula in the constellation Taurus. The nebula is illuminated by the radiation of the variable star RY Tauri.
All the image acquisition info, along with an annotated version of this image, is here in my Astrobin page. A dark nebula (B 214) and a bright nebula (LBN 785) along with a few stars.
This small reflection nebula is usually captured as part of a wide field image of this part of the Taurus Molecular cloud. From my driveway here in the hills of NC, I chose to narrow that view a bit and image it with a RC8 at a focal length of 1628mm using the ASI071MC Pro camera with a Antlia Quadband light pollution filter.
This is 110 3 minute exposures taken Feb 13 and 14, 2024 for 5.5 hours of total exposure.
M51, also known as Messier 51a or NGC 5194, is a spiral galaxy in the constellation Canes Venatici. It’s located 31 million light-years from Earth. M51’s arms are made of long lanes of stars, dust, and gas, and appear like a staircase. Sometimes the designation M51 is used to refer to the pair of galaxies, in which case the individual galaxies may be referred to as M51a (NGC 5194) and M51b (NGC 5195).
The Whirlpool Galaxy has two, very prominent spiral arms that wind clockwise. One arm deviates from a constant angle significantly. The pronounced spiral structure of the Whirlpool Galaxy is believed to be the result of the close interaction between it and its companion galaxy NGC 5195.
As a result of the Whirlpool Galaxy’s interaction with NGC 5195, a variety of tidal features have been created. The largest of these features is the so-called Northwest plume, which extends out to 43 kiloparsecs (140,000 light-years) from the galaxy’s center. This plume is uniform in color and likely originated from the Whirlpool Galaxy itself due to having diffuse gas. Adjacent to it are two other plumes that have a slightly bluer color, referred to as the Western plumes due to their location. These plumes are what I was trying to capture and highlight in my image. Very faint trailing dust.
NGC 5195 (also known as Messier 51b or M51b) is a dwarf galaxy that is interacting with the Whirlpool Galaxy (also known as M51a or NGC 5194). Both galaxies are located approximately 31 million light-years away in the constellation Canes Venatici. Together, the two galaxies are one of the most widely studied interacting galaxy pairs.
A plate-solved and annotated version is available on my Astrobin page.
The Angel Nebula is a reflection nebula and stellar nursery in the Monoceros constellation. It is located about 2,400 light-years away at the edge of the star-forming molecular cloud Monoceros R2.
In this classic celestial still life created with a digital paintbrush the Angel Nebula shines near the image center. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae, a red emission region, many dark absorption nebulae, and a backdrop of colorful stars.
I’ve presented this in a portrait mode to highlight the angel appearance.
Sh2-232, Sharpless 232, referred to as the Great Pumpkin Nebula.
Sh2-232 is a faint, small, and diffused nebula ball in the constellation Auriga. It is located in the pentagon of Auriga, about 3 degrees northeast of IC405.
Sh2-232 is the largest and faintest of a group of diffuse nebulae in Auriga. It is ionized by two giant stars, the O9.5 III HD 37737 and an anonymous B0 II class star.
A unique feature of this target is the Planetary Nebula found in the middle of those three central stars (blue dot) – it’s named PK173+03.1. LDN1525 also features prominently as a black vein. SH2-235 looks like a companion ball of gases.
This image is taken from within the constellation Canes Venatici. My intention was to capture as many galaxies as I could within an image and have them resolvable at a focal length of 840mm.
NGC 4231 and NGC 4232 are the two galaxies at the center of this image. NGC 4232 is a Spiral Galaxy in the Canes Venatici constellation. NGC 4232 and NGC 4231 are situated north of the celestial equator and, as such, are more easily visible from the northern hemisphere. NGC 4231 is a Lenticular Galaxy.
NGC 4218 is an intermediate spiral galaxy between NGC 4232 and M 106. It is 57 million light-years from Earth.
The giant in the image is Messier 106. It is an intermediate spiral galaxy about 23 million light-years from earth. It is one of the largest and brightest nearby galaxies, similar in size and luminosity to the Andromeda Galaxy.
NGC 4217 is an edge-on spiral galaxy at the top of the image, which lies approximately 60 million light-years away. It is a possible companion galaxy to Messier 106. One supernova, SN 2022myz (type I, mag. 19), was discovered in NGC 4217 on 19 June 2022.
To the bottom left is the spiral galaxy, NGC 4220. Estimated at 63.8 million light-years away.
