Excuse Me While I Kiss the Sky -- Month of September 2023

This image shows M55 (NGC 6809). The cluster as a whole appears spherical because the intense gravitational attraction of the stars pull them together. The globular cluster is about 20,000 light-years away in the southern part of the constellation Sagittarius and has a diameter of about 100 light-years. It contains an estimated 100,000 stars with 55 variable stars whose brightness change. Even the great observer Charles Messier had trouble seeing this globular cluster when building his “Catalog of Nebulae and Star Clusters.” It was originally spotted in 1752 by a French astronomer in what is now South Africa, but it took until 1778 for Messier to catalog it. This is because, while Messier 55 is large and reasonably bright, it is lacking a dense core and many of its stars are quite faint, making it hard to observe in non-optimal conditions. For northern observers M55 sits low in the sky, so the view is hampered by the thicker layer of atmosphere as well as water vapor and light pollution. This hindered Messier’s view from his Paris observatory. Even in skies with low light pollution, viewed through binoculars the cluster only appears as a round hazy patch. Small telescopes can begin to resolve individual stars in M55, while larger aperture telescopes will pick out even the low magnitude stars easily. [Video and Content Credits: NASA, the Office of Public Outreach – Space Telescope Science Institute (STScI), JPL – Caltech, Preston Dyches, Christopher Harris, and Lisa Poje with subject matter guidance provided by Bill Dunford, Gary Spiers, and Lyle Tavernier] [Image Credit: Edward Szczepanski, Astromart Gallery Contributor. Taken with Tak FS102 @f/8 on Losmandy G11; SBIG ST2000XM w/CFW8a; guided with ST4; 1000 sec. L, 500 sec. RGB. - https://astromart.com/gallery/photo/19871 ]

Excuse Me While I Kiss the Sky -- Month of September 2023

Welcome to the night sky report for September 2023 -- Your guide to the constellations, deep sky objects, planets, and celestial events that are observable during the month. This September, Venus returns to the early morning skies as a bright beacon in the east, the full moon at the end of the month is a Harvest Moon, and if you have access to dark skies away from urban light pollution, you might be able to glimpse the faint, glowing pillar of the zodiacal light. Pegasus becomes increasingly prominent in the southeastern sky, allowing stargazers to locate globular clusters M2 (NGC 7089), M30 (NGC 7099), as well as a nearby double star, Alpha Capricorni, which is an optical double (but not a binary pair). The night sky is truly a celestial showcase. Get outside and explore its wonders from your own backyard.

After brightening our evening skies for most of this year, Venus has now switched over to being a morning sky object. Look for the superheated, cloud-covered planet as a bright beacon in the eastern sky before sunrise throughout the month. It will appear fairly high in the sky from the Northern Hemisphere – reaching 30 to 40 degrees above the horizon by month's end, depending on your latitude.

Meanwhile, Saturn and Jupiter continue this month as easy-to-observe planets. Find Saturn low in the southeast after sunset, with Jupiter rising a couple of hours later. Saturn then sets a couple of hours before sunrise, leaving Jupiter to rule the sky on its own until the Sun comes up. You'll find Jupiter together with the Moon, high in the southwest before dawn on September 4th.

The full moon on September 29th will be the fourth and final supermoon of the year. Supermoons are full moons that occur when the Moon is near the closest point in its orbit around Earth.

This month's full moon is also known as a Harvest Moon, being the closest full moon to the September equinox. This is around the time when lots of crops in the Northern Hemisphere reach their peak. The harvest moon provides a few days of bright moonlight right after sunset, which traditionally helped farmers have a bit more time to bring in their crops in advance of the first frost.

On cool, moonless September mornings before dawn, you might have an opportunity to search for the zodiacal light. It's a triangular or cone-shaped pillar of faint light that stretches upward from the horizon, and it's easiest to observe around the time of the equinoxes in March and September. The zodiacal light is sunlight reflecting off of an interplanetary dust cloud. This dust fills the inner solar system out to the inner fringes of the main asteroid belt, just past Mars.

In September, Northern Hemisphere skywatchers should look for the zodiacal light in the east during the hour or so before morning twilight begins. Southern Hemisphere observers will want to look to the west in the hour following evening twilight.

Relatively dark skies give you the best chance to observe it and the Moon will be absent from pre-dawn skies during the latter half of September, making zodiacal light easier to spot north of the equator during that time.

Now, most of this dust orbits the Sun in the same plane as the planets do. So it's like looking out, into the disk of the solar system. It's thought to have several potential sources including comets, the planet Mars, and asteroids.

This month we will have an opportunity to study pieces of an asteroid here on Earth, when NASA's OSIRIS-REx mission delivers its samples from asteroid Bennu. The OSIRIS-REx spacecraft collected samples of rocks and dust from the surface of the near-Earth asteroid in 2020, and it's now approaching Earth to return them for study. As it nears Earth, the spacecraft will release its sample return capsule, which will land in Utah on September 24th.

As September brings the transition from summer to fall, so the sky transitions to the stars of autumn. Increasingly prominent in the southeastern sky is Pegasus, the winged horse. The Great Square of stars that outlines the body is a useful guide to the fall patterns around it.

Near the Great Square lies the sprawling pattern of Aquarius, the water-bearer. Located within the western part of the constellation is M2, one of the oldest and largest globular star clusters associated with the Milky Way galaxy. It appears as a circular, grainy glow in backyard telescopes.

NASA’s Hubble Space Telescope has imaged the cluster, a compact globe of some 150,000 stars that are more than 37,000 light-years away. At approximately 13 billion years old, this cluster formed early in the history of the universe, and offers astronomers an opportunity to see how stars of different masses live and die. Results from ESA’s Gaia satellite suggest that this cluster, along with several others, may have once belonged to a dwarf galaxy that merged with the Milky Way.

West of Aquarius is the constellation of Capricornus, the sea goat, a figure dating back to the Sumerians and Babylonians. The star at the western end of Capricornus is Alpha Capricorni. Alpha Capricorni is an optical double but not a binary pair. The brighter star, Algedi, is about 100 light-years away. The fainter star lies along the same line of sight but is roughly eight times farther away.

The pattern hosts another globular star cluster, M30. It appears as a hazy glow in small telescopes. Stars are packed so closely in globular clusters that they can interact with each other. Binary stars can exchange partners in their tight gravitational square dance. More massive objects like black holes and neutron stars move toward the center. M30 likely started life with another galaxy that merged with our own. The globular cluster is orbiting the Milky Way in the opposite direction of most stars.

 Look west to find the constellation Sagittarius, the centaur archer in the sky. Past the centaur’s arm, is a heavily obscured globular cluster, Terzan 5. Terzan 5, which was discovered in 1968 by French astronomer Agop Terzan, sits near the dark dust lanes of the Milky Way. Bright blue young stars are visible in the foreground of the ancient cluster. The core of Terzan 5 shines brightly with the X-ray light from white dwarfs and neutron stars.

Take advantage of mild, late summer nights to enjoy the constellations and ancient globular star clusters of the September sky.

The night sky is always a celestial showcase. Explore its wonders from your own backyard.

The following Deep Sky Objects are found in constellations that peak during the month. Some can be viewed with a small telescope, but the majority will require a moderate to large telescope. The following is adapted from my personal viewing list: "The Guy Pirro 777 Best and Brightest Deep Sky Objects."

Constellation: Aquarius

NGC 6981                    Globular Cluster           M72

NGC 6994                    Open Cluster               M73

NGC 7009                    Planetary Nebula          C55, Herschel 400 H1-4 Saturn Nebula

NGC 7089                    Globular Cluster           M2

NGC 7293                    Planetary Nebula        C63 Helix Nebula

NGC 7606                    Galaxy                         Herschel 400 H104-1

NGC 7723                    Galaxy                         Herschel 400 H110-1

NGC 7727                    Galaxy                         Herschel 400 H111-1

     - NGC 7724             Galaxy                              - Paired with H111-1

Constellation: Capricornus

NGC 7099                    Globular Cluster             M30                  

Constellation: Cepheus

Caldwell 9                   Diffuse Nebula               C9 Cave Nebula

IC 1396                        Open Cluster              P6 Elephant Trunk Cluster

NGC 40                        Planetary Nebula        C2 Herschel 400 H58-4 Bow Tie Nebula

NGC 188                      Open Cluster               C1

NGC 2300                    Galaxy                        P220

     - NGC 2276             Galaxy                              - Paired with P220

NGC 6939                    Open Cluster               Herschel 400 H42-6

NGC 6946                    Galaxy                        C12, Herschel 400 H76-4

NGC 7023                    Open Cluster                C4 Iris Nebular Cluster

NGC 7142                    Open Cluster                 Herschel 400 H66-7

NGC 7160                    Open Cluster                 Herschel 400 H67-8

NGC 7226                    Open Cluster                 P140

NGC 7235                    Open Cluster                 P7

NGC 7261                    Open Cluster                 P8

NGC 7380                    Open Cluster                 Herschel 400 H77-8

NGC 7510                    Open Cluster                 Herschel 400 H44-7

NGC 7762                    Open Cluster                 P141

Constellation: Lacerta

IC 1434                        Open Cluster              P159

IC 1442                        Open Cluster              P160

IC 5217                        Planetary Nebula          P230

NGC 7209                    Open Cluster                Herschel 400 H53-7

NGC 7243                    Open Cluster                 C16, Herschel 400 H75-8

NGC 7245                    Open Cluster                 P161

NGC 7296                    Open Cluster                 Herschel 400 H41-7

Constellation: Pegasus

NGC 7078                    Globular Cluster            M15

NGC 7217                    Galaxy                         Herschel 400 H207-2

NGC 7331                    Galaxy                         C30, Herschel 400 H53-1

NGC 7448                    Galaxy                         Herschel 400 H251-2

NGC 7457                    Galaxy                         P173

NGC 7479                    Galaxy                         C44, Herschel 400 H55-1

NGC 7814                    Galaxy                         C43

Constellation: Sagittarius

IC 4684                        Diffuse Nebula           P182

IC 4725                        Open Cluster               M25

IC 4776                        Planetary Nebula           P183

NGC 6440                    Globular Cluster            Herschel 400 H150-1

NGC 6445                    Planetary Nebula          Herschel 400 H586-2 Little Gem Nebula

NGC 6469                    Open Cluster               P184

NGC 6494                    Open Cluster                M23

NGC 6507                    Open Cluster                 P185

NGC 6514                    Diffuse Nebula               M20, Herschel 400 H41-1 Trifid Nebula

NGC 6520                    Open Cluster                 Herschel 400 H7-7

NGC 6522                    Globular Cluster             Herschel 400 H49-1

NGC 6523                    Diffuse Nebula                M8 Lagoon Nebula

NGC 6528                    Globular Cluster              Herschel 400 H200-2

NGC 6530                    Open Cluster                  P49

NGC 6531                    Open Cluster                   M21

NGC 6540                    Globular Cluster               Herschel 400 H198-2

NGC 6544                    Globular Cluster                Herschel 400 H197-2

NGC 6546                    Open Cluster                     P106

NGC 6553                    Globular Cluster                 Herschel 400 H12-4

NGC 6558                    Globular Cluster                  P107

NGC 6561                    Open Cluster                      P186

NGC 6563                    Planetary Nebula                 P187

NGC 6565                    Planetary Nebula                 P248

NGC 6567                    Planetary Nebula                 P188

NGC 6568                    Open Cluster                         Herschel 400 H30-7

NGC 6569                    Globular Cluster                     Herschel 400 H201-2

NGC 6583                    Open Cluster                          Herschel 400 H31-7

NGC 6590                    Open Cluster                          P50

NGC 6603                    Open Cluster                          M24 Small Sagittarius Star Cloud

NGC 6613                    Open Cluster                          M18

NGC 6618                    Open Cluster                          M17 Omega Nebula

NGC 6624                    Globular Cluster                     Herschel 400 H50-1

NGC 6626                    Globular Cluster                     M28

NGC 6629                    Planetary Nebula                    Herschel 400 H204-2

NGC 6637                    Globular Cluster                     M69

NGC 6638                    Globular Cluster                     Herschel 400 H51-1

NGC 6642                    Globular Cluster                     Herschel 400 H205-2

NGC 6645                    Open Cluster                         Herschel 400 H23-6

NGC 6647                    Open Cluster                         P108

NGC 6652                    Globular Cluster                     P31

NGC 6656                    Globular Cluster                     M22

NGC 6681                    Globular Cluster                     M70

NGC 6715                    Globular Cluster                     M54

NGC 6716                    Open Cluster                         P109

NGC 6717                    Globular Cluster                     P110

NGC 6723                    Globular Cluster                     P52

NGC 6809                    Globular Cluster                     M55

NGC 6818                    Planetary Nebula                    Herschel 400 H51-4

NGC 6822                    Galaxy                                  C57 Barnard’s Galaxy

NGC 6864                    Globular Cluster                     M75

For more information:

Northern Latitudes:

https://hubblesite.org/resource-gallery/learning-resources/tonights-sky

https://nightsky.jpl.nasa.gov/planner.cfm

https://solarsystem.nasa.gov/skywatching/home/

https://solarsystem.nasa.gov/skywatching/whats-up/

https://www.cfa.harvard.edu/skyreport

http://outreach.as.utexas.edu/public/skywatch.html

https://griffithobservatory.org/explore/observing-the-sky/sky-report/

http://www.beckstromobservatory.com/whats-up-in-tonights-sky-2/

https://www.fairbanksmuseum.org/planetarium/eye-on-the-night-sky

http://dudleyobservatory.org/tonights-sky/

https://cse.umn.edu/mifa/starwatch

http://www.schoolsobservatory.org.uk/learn/astro/nightsky/maps

https://tonightssky.com/MainPage.php

https://earthsky.org/astronomy-essentials/visible-planets-tonight-mars-jupiter-venus-saturn-mercury

https://www.timeanddate.com/astronomy/night/

https://stardate.org/nightsky

https://www.adventuresci.org/starcharts

https://www.astromart.com/news/search?category_id=3&q=kiss+the+sky&from=&to

Equatorial Latitudes:

https://heavens-above.com/SkyChart2.aspx

https://in-the-sky.org/data/constellations_map.php

https://ytliu0.github.io/starCharts/chartGCRS.html

Southern Latitudes:

https://www.scitech.org.au/explore/the-sky-tonight/

https://www.stardome.org.nz/star-charts--sky-spotter

Watch Satellites Pass Over Your Location:

https://james.darpinian.com/satellites/

Astromart News Archives:

https://www.astromart.com/news/search?category_id=3&q=.

Check out some of my favorite Words of Wisdom:

https://astromart.com/news/show/words-of-wisdom-my-favorite-quotable-quotes

https://astromart.com/news/show/words-of-wisdom-my-favorite-proverbs-from-around-the-world

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