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The Andromeda Galaxy with a Pair of Binoculars

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Feature illustration:  The Andromeda Galaxy Sky Area. Excerpted from https://in-the-sky.org/skymap.php.  The excerpt is set to November 24, 2023 at 9:00 PM from Reston, VA, but any time and location may be selected.  Notice the Great Square of Pegasus and the red oval above it.

Article by and illustrations courtesy of FMN Stephen Tzikas

The Andromeda Galaxy is an object often mentioned in sci-fi films and

Illustration by author: 1979 sketch of Andromeda Galaxy, using a 60mm Selsi refractor telescope and 187.5 magnification.

literary works.  It is our closest galaxy (not including Milky Way satellite galaxies) and can be seen by the naked eye in a dark sky location.  I was thrilled to see it through my childhood telescope.  With binoculars it is a fuzzy patch-like object.  That little patch is just the central core or brightest part of the galaxy.  The rest of the galaxy is so dim because of its 2.5 million light year distance.  If we could brighten the galaxy, it would be four full Moon lengths across the sky.  The central core of the Andromeda Galaxy with a pair of binoculars looks very similar to my 1979 illustration of it through a Selsi 60mm telescope.  The area around the Andromeda Galaxy is also home to other surprises too.

Close-up of the Andromeda Galaxy Sky Area.  Nu-And (magnitude 4.5) is the bright star to the upper left of the Andromeda Galaxy outline. The diagram’s center bright star, with green constellation line underneath, is Mu-And (magnitude 3.9).  The bright star in the center-left is Mirach (magnitude 2.1) with NGC 404 (red dot) next to it.  This illustration is also excerpted from https://in-the-sky.org/skymap.php for Nov. 24, 2023 at 9:00 PM.

A pair of binoculars can see EG Andromedae (EG And), a variable star. You can take measurements of it brightening and dimming via a visual comparison to nearby stars that are fixed in brightness. You can obtain a detailed star chart for measuring magnitude changes through the Variable Star Plotter at the AAVSO website and then inputting EG And. You can submit your measurements to their database. See https://app.aavso.org/vsp/

With a small telescope a little larger than binoculars, two more interesting objects can be seen nearby.  One is a beautiful

Excerpted from http://informationaboutstars.com/starinfo.dc/star/id-36618/.  The website is from “about the stars Planetarium” on HIP 3495, a.k.a. EG Andromedae in the constellation Andromeda. The star varies in magnitude from 6.97 to 7.8, and is circled adjacent to the Andromeda Galaxy.  In another blue circle, Nu And is to the upper left of EG And. 

double star named gamma Andromedae, or Almach. Through the telescope it appears as a bright, golden-yellow star next to a dimmer blue star. Some observers may get the impression that the blue star has a green hue. This green hue is an optical illusion caused by the contrast of the colors on the eyes and is very rare to see.  In actuality, there are no green stars, because any star emitting radiation in the green spectrum is also emitting enough red and blue radiation to combine and form white light. This double star, along with the double star named Albireo in the constellation Cygnus, are often described as the most visually colorful double stars in the sky.

The other nearby interesting object is beta Andromedae, or Mirach. It is a prominent orange/red hue star northeast of the Great Square of Pegasus. The galaxy NGC 404, also known as Mirach’s Ghost, is seven arcminutes away from Mirach. In a small telescope, it appears as a fuzzy star.  NGC 404 is located about 10 million light years away, or about 4 times Andromeda Galaxy’s distance.  Though NGC 404 is not as large or bright as the Andromeda Galaxy, is still worth a look.  It is easy to find, and a one of the brighter magnitude galaxies to observe in the sky.

Mira, A Spectacular Variable Star

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The Online Planetarium (In-The-Sky.org) star map snap shot, showing the location of Mira (circled) at 5:00 AM on June 15, 2023 in the eastern sky. Mira might be hard to see until later in the summer.

Illustrations and article by FMN Stephen Tzikas

When does a bright star come out of nowhere, rise in the east, and attract a gathering of followers? It might sound like a familiar story about a star in the east a couple millennia ago. However, this star repeats a cycle every 11 months, and is an attention getting event in the constellation Cetus. The star is Omicron Ceti, otherwise known as Mira by its common name. It is my favorite variable star and I track it continuously when it is not behind the Sun, which makes it unobservable for a few months. Mira is unique in that its brightness varies from nearly a magnitude of 2 to dimmer than magnitude 9. This means that at its brightest, it is one of the brightest stars in the sky. At its dimmest, it is invisible and a telescope is needed to see it. One can watch it over the weeks, even as short as days, and see it growing brighter and then dimmer. Serious observers like myself will submit their observations to the American Association of Variable Star Observers (AAVSO). There are many other variable stars that one can observe, and some of them have cycles that are entirely naked eye. But observing with binoculars opens many opportunities. There are many reasons why a star can regularly vary in brightness.

Mira is part of a group of variable stars called long-term Mira variables, named after Mira itself, the most famous

Light curve for Mira produced by all observers, including the author. Notice the sinusoidal manner in which Mira varies in brightness over the months and years. The orange markers are the author’s contributions.

of this type of star. Mira type variable stars are red giant stars in the later stages of evolution, and they pulsate with cycles longer than 100 days, and with amplitudes greater than 2.5 in visual magnitude. They will eventually become white dwarf stars at the center of a planetary nebula, the remains of the original star’s dissipated outer envelope.

I track the brightness of Mira by comparison to the known brightness magnitudes of neighboring stars that do not change in magnitude. When at its brightest, I track Mira’s changes in magnitude visually. When it is dimmer, by binoculars. At its dimmest, I need a telescope.

Mira will be at brightest again in June 2023. Mira just passed its dimmest magnitude in January 2023. The challenge this year is that Mira will be its brightest at early dawn rising in the eastern sky. That may make it unfavorable for some people to see, but as we get into the summer months, Mira will be higher and higher in the eastern sky before sunrise and probably still a naked eye object depending on your location’s light pollution.

Light curve specific for the author’s input since 2013, with other observer contributions removed.  This contribution is thus one part of a more complete light curve.

One can check the magnitude of Mira on the AAVSO website (https://www.aavso.org/). Besides Mira there are other common naked eye variable stars that can be observed. Learn more at: https://www.astroleague.org/al/obsclubs/variablestar/VSOIntroduction.html, the Astronomical League’s variable star program.

 

The Southern Celestial Sky of Fairfax County

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A twilight view of the southern sky from Lake Audubon on January 26, 2022.

Article and photo by FMN Stephen Tzikas

You may realize that the southern hemisphere has the awesome Magellanic Clouds in its night sky.  Some of us may never get to the southern hemisphere, but there are certain visible stars from Fairfax County that you probably never thought possible.

My first encounter with the southern hemisphere sky was in 1983 when I commenced my Master’s degree in engineering at the University of New South Wales, just outside of Sydney, Australia.  On the first night of my arrival I was so excited to run outside the International House dormitory in order to see the Magellanic Clouds. There they were, in addition to the Southern Cross, the very bright Alpha Centauri star, and the “upside down” constellations and Moon.  Where it not for the incredibly long double air flights to reach Sydney, I probably would have been too excited to sleep that night.

If you have done any star gazing or have joined a local astronomy club you may be familiar with the Astronomical League and its incredible astronomy observing programs:

https://www.astroleague.org/al/obsclubs/LevelObservingClubs.html

As an avid astronomical observer since I was a child, I have completed most of the Astronomical League’s observing programs.  Scroll down that link’s list of observing programs and you see the novice program called Constellation Hunter Observing Program – Southern Skies.  I did this program from Fairfax County in a very creative manner.  While I was in Australia as a student, I did all of my observing by naked eye and from the lawn of the University campus.  Fortunately my notes included all the amazing things close to the southern celestial pole.  But, from Fairfax County, I was able to reobserve most of the constellation stars in some greater detail.   Let me explain, because you can do the same. 

A screen shot of the very useful on-line Planetarium offered by In-The-Sky.org at https://in-the-sky.org/skymap.php.  You can use this site to plan what is in your southern sky on a particular night and time.

I live in Reston, and the coordinates of my town are 38.9586° N, 77.3570° W.  For all practical purposes they are the coordinates of Fairfax County.  Because we are just under 39 degrees from the equator, we can see a full 90 degrees south beyond our location.  Subtracting 39 from 90 degrees, means we can see as far as 51 degrees south of the equator.  For the casual stargazer, he or she is usually content with the stars of the ecliptic (the Sun’s apparent path across the sky) and points north to Polaris, the northern star.  But if you look south, you’ll see a parade of constellations marching past you each night and through the seasons along the southern most visible latitude arc of the Earth as seen from Fairfax County.  I live next to Lake Audubon, and there are places along the lake where there is a clear view of the southern sky directly opposite to the northern star.  The tree line and homes are only about 4 degrees above the horizon, and that is pretty good, especially on winter evenings or mornings where the tree line is also partially transparent due to the loss of foliage.

What exactly can be seen?  Most of us are familiar with the northern constellations and those of the ecliptic. Those are constellations with names such as the “Big Dipper,” Cassiopeia, Orion, Hercules, Virgo, Scorpius, Sagittarius, Cygnus and so on.  Some of you may even be familiar with some of the bright stars in our Fairfax County sky like Vega, Rigel, and Betelgeuse, some of which take on blue and red hues.  There are 88 constellations so I rather not name all the common stars and constellations seen from Fairfax County.  But under (i.e., south of) the ecliptic there are some constellations that can be seen in their near entirety if you find a clear spot, like one on Lake Audubon.  These include  Piscis Austrinus with its bright blue star Fomalhaut, as well as the constellations of Microscopium, Sculptor, Fornax, Caelum, Columba, Pyxis, Antlia, Telescopium, and Lupus.  Not only that, but there are even more southern sky constellations that reveal a good chunk of themselves, such as Centaurus, Vela, Phoenix, Grus, Corona Australis, and Norma.

The most challenging stars are those that form parts of constellations that are barely above our horizon.  On one night I was very excited to see the bright stars called alpha and delta Horologii. On another night I observed sigma Arae.  Under the constellation Columba, specifically just under the star eta Columbae, the constellation Pictor begins.  With a telescope it would be possible to see some of the more fainter stars in that constellation. Finally, really close to the horizon (so you’ll need to find an extraordinary viewing site), it would be possible to see alpha or zeta Indi.

As we get closer to the horizon, the thicker atmosphere extinguishes the brightness of stars.  Having a pair of binoculars will assist.  For those who love astronomy, this is a star gazing activity, naked eye or with binoculars, that is an enjoyable effort to find those hidden and exotic gems of the southern sky.

Natural History Field Study: Night Sky for Naturalists, Wednesdays, February 9th – March 16th

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Photo by Andy Holmes on Unsplash

February 9 – March 16, 2022
Wednesdays, 6 – 8 pm
Class is hybrid with both Zoom lectures and in person field trips.
$200/ANS members; $250 nonmembers
Register here.

This Audubon Naturalist Society course provides a basic introduction to astronomy that emphasizes appreciation of Earth’s relationship to the universe. Topics covered include the celestial sphere, celestial navigation, motions of the Sun, Moon, planets, and stars, telescopes, timekeeping, phases and motions of the Moon, tides, and eclipses. Field trips will provide hands-on experience with telescopes at the Montgomery College Astronomical Observatory, including both solar and nighttime observing.