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San Geronimo Lodge
Dark Sky Taos Astronomy Program -- Fall 2003

Welcome to the San Geronimo Lodge Dark Sky Taos Astronomy Program! By way of introduction let us welcome you here and generally review the ambitions of this relatively informal program.

The main goal of the program is for you to enjoy and respect the fabulous clarity and darkness of the skies here in New Mexico. I would say that just to look up with admiration would be great, but if you wish we will then proceed on a simple tour of some of the major constellation groups of the late summer -- early autumn skies. The outlines and material following this page of introduction is for you to use during the program and then keep. Please feel free to take notes and ask questions. These materials consist of star charts and outlines and descriptions of the constellations and telescopic objects we hope to "visit." The descriptions are from Norton's Star Atlas, the Mullaney/McCall list of The Finest Deep-Sky Objects and my own. I would suggest that these outlines will only be used as guides; review them more carefully at a later date. Enjoy the New Mexico skies now while we are under them.

We call this observing session the Dark Sky Taos Astronomy Program because we have chosen to observe under a moonless night. The moon does have an adverse effect on the naked-eye views of both star constellations and the telescopic views of deep-sky objects as discussed below.

The main goal of the program is for you to enjoy and respect the fabulous clarity and darkness of the skies here in New Mexico.

Our procedure will be to first do a naked-eye tour of the constellations and then proceed with viewing through the telescope. We'll use a very manual Classic Celestron 8" telescope. Some of the very best objects we anticipate viewing are in the southern constellation of Sagittarius; as such we will probably view these objects first and then proceed to the others. During viewing it is best not to experience any "white" light, as this sort of light will ruin our night vision by decreasing our pupil size and thereby not allowing our eyes to be able to see the hazy nuances of some of the dimmer deep-sky objects. We'll try to provide some red flashlights as the human eye is much less affected by this color. The general "style" will be to find an object and then take turns viewing it though one or both telescopes. During the viewing the object ought to stay in view as the telescope has a motorized drive that mimics the rotation of the Earth, (hopefully!) then guiding accurately on the object in view. I'll, of course, be there to assist in the viewing technique and in trying to answer most of your questions. After the viewing session we can talk further and you can always contact me by e-mail or visit my photography web sites and even sign up for the on-line newsletters. We sincerely hope you enjoy the program. Thanks!

Willis Greiner and Cheryl Price

Please also visit Cheryl's original fine art watercolor web sites at:



Dark Sky Taos Astronomy Program -- Fall 2003

Observation Program -- Constellations


Look North

Ursa Major [Big Dipper] Polaris and Ursa Minor [Little Dipper]
Cassiopeia, Perseus and Andromeda / Pegasus

Look Up (following Milky Way / our home Galaxy)

Cygnus [Northern Cross]
Summer Triangle of Stars including Deneb (in Cygnus), Vega (in Lyra) and Altair (in Aquila)

Look South (continuing to the center of the Milky Way)



Observation Program -- Telescopic Deep-Sky Objects


Open star cluster NGC 2158 in Gemini

Open Star Clusters

Open Star Clusters are loosely compressed, often irregular groups of related stars. They are most numerous in our winter sky, and often are the most impressive objects seen in small telescopes. They exist in our galaxy and are relatively close by.

Double Cluster / Perseus

Two magnificent clusters, visible to the naked eye, and fine objects even in small telescopes; the diameter of each is about 45'. There is a fine ruby star near the center of cluster 884. Together they rate as the finest open star clusters for small telescopes and are superb in any. With larger instruments only one at a time can be fitted into the field of view. Both clusters are about 7000 light years from us

M 11 [Wild Duck Cluster] / Scutum

A grand, fan-shaped cluster, with a bright star at the apex. Dark structures to the south. M 11 is the finest open cluster north of -40 degrees for larger instruments. Very rich and compact, it has a bright star near its center. Here as in M 4 we get the impression of dark lanes crossing the cluster. Resolved in a 4-inch at 80x, M 11 is one of the few open star clusters rich enough to be striking even in a 30-inch telescope.


Obscuring Horsehead Nebula in Orion
Emission Flame Nebula in Orion

Diffuse Emission Nebulae

Diffuse Emission Nebulae are irregular areas of gas (often seen with obscuring dark nebulae) that may be the birthplace of new stars within our galaxy. Common examples are the Great Orion Nebula and the Lagoon Nebula. The classic Horsehead Nebula is an example of a dark obscuring nebula. These nebulae are probably areas of recent activity and great heat.

M 8 [Lagoon Nebula] / Sagittarius

appears as a nebulous patch traversed by a large dark lane and with a scattered open cluster (NGC 6530) to one side. A 3-inch easily shows the nebula and cluster but not the lane. Very nice in a 10-inch at 80x.

M 17 [Omega Nebula] / Sagittarius

is the Horseshoe or Omega Nebula. It can be well seen in a 3-inch telescope. A 10-inch shows it as a long ray, hooked at one end and crossed by dark lanes, It is near the densest section of the Milky Way.


Planetary Crab Nebula in Taurus

Planetary Nebulae

Planetary Nebulae are small gaseous areas within our Milky Way. These nebulae are commonly thought to be the remnants of super novae explosions that have occurred over time. Perhaps the most famous of these nebulae is the hard-to-see Crab Nebula in the constellation of Taurus. It is thought to the remnant of a super nova that happened in the 11th century. Many planetaries have dim central stars, perhaps the white dwarf that the super nova produced. The central stars of most planetaries are only visible with large observatory instruments or with long-exposure photography.

M 57 [Ring Nebula] / Lyra

In the same constellation that features Vega (one of the 3 Summer Triangle Stars, and the brightest star now in the sky), M 57 (the famous Ring Nebula) is considered the finest of all planetary nebulae. Its central hole is seen at 100x with a 3-inch. Excellent with an 8-inch at higher magnifications. The central stars are only seen with large instruments or with long-exposure photography.

M 27 [Dumbbell Nebula] / Vulpecula

is easily seen in a 3-inch. It is much larger than the Ring Nebula, and has excellent surface brightness. With dark skies its unique shape is obvious, even with a 3-inch.


Globular star cluster M 15 in Pegasus

Globular Clusters

Globular Clusters are very tightly compressed star clusters which happen to congregate at the edges of our and other galaxies. It is through the observation and measurement of the "Cepheid variable stars" in these clusters that have led us to the conclusion that our Milky Way is, in fact, a spiral galaxy much like the Great Andromeda Galaxy.

M 22 / Sagittarius

is rated as the finest globular cluster after M 13 in the sky north of -40 degrees. A 3-inch at 45x shows a fuzzy ball, at at 90x begins to resolve it. It is easily resolved to the center with an 8 to 10-inch scope. About 10,000 light-years distant from us, M 22 is one of the nearest globulars.

M 13 / Hercules

is the finest globular north of -40 degrees. A 3-inch at 90x begins to resolve it; an 8-inch will resolve the entire cluster and shows many faint stars.


Multiple Stars

Multiple Star systems are common. Many of these systems have related members (that is, the components orbit about a common point) and can be seen over time as changing. Some of the systems contain "eclipsing" stars, which then makes them appear to change in brightness as one star (perhaps with less luminosity) passes in front of the other. These motions can be accurately measured and the distance from Earth then established. This concept is very important as it relates to the "Cepheid variable" double star systems. These "Cepheid variables" have been found in globular clusters in our galaxy and also in other "island universes." Their existence has helped to put a scale both on our Milky Way and beyond. Some (the minority) "double stars" are just lined up with each other as viewed from Earth and are not related.

Albireo / Cygnus

is a beautiful pair separated by 35". The distinct colors (orange and blue) seem more obvious in a 3-inch than in a larger telescope. As is the case with almost all doubles, these stars are related and rotate about a common point.

Mizar / Ursa Major

is considered by many to be the finest double for smaller instruments. The components are both white. This is a great multiple system for comparing what the naked-eye sees to what the telescope reveals.


Edge-on spiral galaxy NGC 891 in Andromeda


Galaxies contain millions of stars and are "separate island universes." Our galaxy (the Milky Way) and several others (including the Great Andromeda Galaxy and the Small and Large Magellenic Clouds) make up The Local Group of nearby galaxies, the closest being some 2 million light years from us. The farthest objects ever recorded (by the Hubble Space Telescope) are galaxies some 12 billion light years away. Because it has taken 12 billion years for their light to reach us, it can be positively inferred that our universe is at least 12 billion years old.

M 31 [the Great Andromeda Galaxy] / Andromeda

is the finest representative in its class of objects. A 3-inch shows a featureless but bright ellipse, but a larger instrument (perhaps a 13-inch) shows some dark structure (indicating spiral arms seen obliquely) and a small starlike nucleus. This galaxy, part of the local group, is about 2 million light years from us.


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