Marsh Creek State Park, April 13th, 2024

The Pleiades, M45

The Pleiades star cluster is also known as the Seven Sisters, and as Messier 45. It is a prominent object in the night sky with a conspicuous place in ancient mythology. The cluster is among the nearest to Earth, and the most obvious to the naked eye. Although only a handful are visible to the unaided eye, it contains hundreds of stars, some of them surrounded by swirls of nebulosity. 

The Great Orion Nebula, M42

The Orion Nebula, catalogued as Messier 42 or NGC 1976, is one of the brightest nebulae in the sky, and one of the nearest star-forming regions to Earth. It is rewarding in telescopes of every size, and is perhaps the most studied and photographed object in the sky. M 42 is visible to the naked eye as a hazy patch surrounding Theta Orionis, the middle star in the Sword of Orion, just south of Orion's Belt. 

The Moon

The Earth's companion in its orbit around the Sun is the Moon. The Moon orbits the Earth at an average distance of about 240,000 miles (384,000 km) over a period of about 29.5 days. Its monthly cycle of phases provided a natural clock for ancient societies; most human calendar systems are built around, or least contain units based on, the orbital period of the Moon. To this date, the Moon is the only object in the solar system other than the Earth that has been visited by humans. 

M81

Messier 81 (NGC 3031) in Ursa Major is one of the most conspicuous spiral galaxies in the sky. It forms a physical pair with its neighbor, M 82, and is the dominant galaxy of the M81 group. Discovered along with M 82 by Johann Bode, and sometimes referred to as Bode's Nebula, M 81 is one of the easiest and most rewarding galaxies for amateur astronomers in the northern hemisphere. 

M82

Messier 82 (NGC 3034) is a remarkable, peculiar galaxy in Ursa Major. M 82 was discovered along with its partner M 81 by Johann Bode, and both galaxies are sometimes known as Bode's Nebulae. Also called the Cigar Galaxy, M 82 has been spectacularly disturbed by a relatively recent encounter with M 81, and displays conspicuous dust lanes and heavy star formation. M 82 is the prototype irregular starburst disk galaxy. 

Jupiter

Jupiter is the largest planet in the solar system, and by far the most massive. It contains over twice as much matter as all of the other planets combined. Jupiter is a very different planet from the Earth, or any of the other inner planets. It is composed mostly of liquid and gaseous hydrogen, and has no solid surface. For this reason, Jupiter is the first of the "gas giant" planets 

Uranus

Uranus is the seventh planet from the Sun, and was the first to have been discovered in recorded history. It is unique because its rotational axis is radically tilted towards its orbital plane, and its moons also have orbits that are tilted with respect to Uranus's orbital plane. 

Comet 12P/Pons-Brooks

12P/Pons-Brooks is a periodic comet discovered on July 12, 1812 by Jean-Louis Pons. It was later found independently by Vincent Wisniewski and Alexis Bouvard in August of the same year. Shortly after its initial discovery, Johann Franz Encke determined a definitive orbit for the comet, with a period of 70.68 years. This orbit was used to generate an ephemeris for the 1883 return. But searches were unsuccessful until the comet was accidentally rediscovered by William Robert Brooks on September 2nd, 1883, and later identified as the same object. 

Pons-Brooks fits the classical definition of a Halley-type comet, with an orbital period between 20 and 200 years. With a steep orbital inclination of 74.2°, this comet does not spend a lot of time near the ecliptic, where it is easiest to interact with other bodies. The comet's orbit appears to be stable between 1740 and 2167, with no strong perturbations by any of the planets. It will next appear in 2024.

In 2011, Mexican astronomers suggested that this comet may have split into several pieces around 1883, and that Earth barely avoided multiple Tunguska events or even a mass extinction. On August 12-13, 1883, Mexican astronomer Jose Bonilla observed 447 bodies with a "bright mistiness" cross the solar disc from an observatory in Zacatecas. These objects were estimated to have had a size between 46 and 1022 meters, and to have passed only 538 to 8062 km from the Earth. The source of these objects could also have been comet C/1883 D1 (Brooks-Swift), or another unknown comet. The event also coincided with the annual Perseid meteor shower; even migrating birds cannot be ruled out.

Starfest, August 19th, 2023:

Messier 13 - Globular Cluster in Hercules

Globular clusters are gravitationally bound concentrations of approximately ten thousand to one million stars, spread over a volume of 30 to about 200 light years in diameter.  M 13 is one of the most prominent and best known globular clusters of the northern celestial hemisphere, 165 light years away from Earth. Towards its center, stars are about 500 times more concentrated than in our solar neighborhood. Globular Clusters are among the oldest objects in the Universe, appearing to be formed of light elements more associated with the primordial universe. Scientists do not understand what formed globular clusters or why they survived so long.  Image

Messier 11 - Open Cluster in Scutum

M 11 is an Open cluster, about 24 light years away from Earth. Open (or galactic) clusters are physically related groups of stars held together by mutual gravitational attraction.  They are believed to originate from large cosmic gas and dust clouds in the Milky Way, and to continue to orbit the galaxy throughout the disk.  Most open clusters have only a short life as stellar swarms.  As they drift along their orbits, some of their members escape the cluster, due to velocity changes in mutual close encounters, tidal forces in the galactic gravitational field, and encounters with field stars and interstellar clouds crossing their way.  An average open cluster has spread most of its member stars along its path after several 100 million years; only a few of them have an age counted in billions of years.  Most of the individual stars in the sky are thought to original from open clusters.  Image

Alberio, A Binary (Double) Star in Cygnus

Binary stars are two stars held together by mutual gravitational attraction. The stars in a binary system orbit around a common center of gravity.  Binary systems are different from “optical” double stars, which are stars separated by great distances laying in nearly the same line of view (i.e., they are not interacting).  Considered to be among the most beautiful of double stars, Albireo is a favorite of new and veteran astronomers alike.  Its colors are vibrant – golden yellow (larger star) and azure blue (smaller star).  Its location in Cygnus, a prominent summer constellation, makes it easy to find, 390 light years away from Earth.  Cygnus also has a double star with an orbiting planet around 16-Cygni B. Image

Messier 57 - A Planetary Nebula in Lyra

Known as a Planetary Nebula because, in a small telescope, M 57 appeared as a resolved (focused) planetary disk.  Of course, it has no relation to a planet.  The Ring Nebula, which is 4,100 light years away from Earth, formed when the star’s hydrogen was depleted by fusion to helium and successive elements.  The resulting loss in heat caused the outer shells of gas to collapse onto the core.  The shock of this collapse caused the violent expulsion of much of the outer shells of gas.  This event is known as a Super Nova.  The hotter remnant core emits enough UV radiation to ionize what used to be the outer layers of the star.  The object is thought to appear as a ring because we are looking down a tunnel of gas ejected by the star at the end of its nuclear-burning life.  It’s believed the object might look similar to the Dumbbell Nebula if viewed from the side (Messier 27, #9 on this list).  Image

NGC 6503 - A Galaxy in Draco

NGC 6503 is considered a dwarf spiral (roughly 1/3 the Milky Way’s diameter). It is a strong x-ray source, and may harbor a massive black hole near the center of the galaxy. A galaxy is a giant association of stars, interstellar gas and dust.  They are classified into three main types: Spiral, Elliptical and Irregular.  The sizes of these island universes range from a few thousand to 150,000+ light years in diameter.  Star number of stars in these objects can be from millions to trillions.  Our Milky Way Galaxy is an average to above average spiral galaxy about 100,000 light years across, containing approximately 300,000,000,000 stars! NGC6503 is 17,000,000 light years away from Earth -the light you see from this object left the galaxy 17 million years ago.  Image

Messier 22 - A Globular Cluster in Sagittarius

M 22 is visible to the naked eye and as impressive as M 13 in Hercules. It contains an estimated 70,000 stars, is 10,000 light years away from Earth, and It is moving away from earth at approximately 333,000 miles per hour! The Hubble Space Telescope has photographed a considerable number of planet-sized objects that appear to float within the cluster.  These objects may have masses of only eighty times that of earth. One of four known Globular Clusters to have a planetary nebula within the boundary of the Cluster.  Image

Messier 17 - An Emission Nebula and Star Cluster in Sagittarius

M 17 is often called the Omega Nebula or Swan Nebula and star formation in M 17 is either still active or ceased very recently.  A small cluster of about 35 bright, but obscured, stars seems to be imbedded in the nebulosity.  Star Clusters are stars that formed together, and are bonded by their mutual gravity. Galactic Nebula, and in this case emission nebula, are clouds of interstellar matter of mostly hydrogen gas.  They are places of star formation.  Newly formed stars excite the gas of the nebula and make it shine.  This object is estimated to be 5,500 light years away from Earth.  Image

Messier 8 - An Emission Nebula in Sagittarius

Galactic nebula, and in this case emission nebula, are clouds of interstellar matter of mostly hydrogen.  M 8 is one of the most studied objects of its type and it is named "Lagoon" for the band of dust streaming through the center of the nebula. These enormous clouds of gas are the birthplaces of stars.  Radiation from stars within the cloud excites the gas and makes it shine (emit light) as a nebula.  Within the brightest part of the Lagoon Nebula, is a shape is called the "Hourglass Nebula".  This feature was discovered by John Herschel and occurs in a region where intense star formation processes appear to be taking place. The bright emission is caused by heavy excitation of very hot, young stars. It is about 5,200 light years away from Earth.  Image

Messier 27 -  A Planetary Nebula in Vulpecula

M 27 is a Planetarty Nebula, about 1,000 light years away from Earth. Planetary nebulae are gas ejected from a dying star.  The core of the star is often called a white dwarf.  Radiation emitted by the star excites the ejected, expanding gas and makes it shine.  Our Sun will have the same fate in about 5 billion years.  At that time, it is expected to expand to become a Red Giant, occupying a space that will envelope earth and possibly Mars.  M27 was the first Planetary Nebula discovered in 1764 by Charles Messier.  Image

NGC 6826 - A Planetary Nebula in Cygnus

NGC 6826 is commonly referred to as the "Blinking Nebula" or "Blinking Planetary."  When a star with an intermediate mass (80% of the Sun, but less than 8 times the Sun’s mass) runs out of sufficient fuel to maintain its equilibrium, it dies and, in the process, swells to form a red giant star.  As the star expels gas, its core contracts and temporarily radiates energy again.  This energy ionizes the expelled gas causing it to emit light.  In the case of NGC-6826, the bright core overwhelms the human eye, preventing one from seeing the surrounding gas (the emission nebula).  However, it can be viewed using averted vision, looking next to the central star, which causes it to "blink" in and out of view.  Look carefully and you may see the two bright patches on opposite sides of the nebula.  The Blinking Nebula is about 2,200 light years away from Earth.  Image