Amphitheater before a night of observing.
If interested in a private party, details can be found on the Private Star Party page.
Public star parties are free and open to the public.
Location noted if other than Hidden Valley Observatory.
Please note that the events are held “weather permitting”. An announcement of a postponement to the following night or cancellation will be made on facebook.com/sdbhas.
A video related to that evening’s theme, determined the night of the event, will be shown in the outdoor amphitheater. Observing will follow the video. The observatory telescope is broadcast to a large screen television inside the observatory and members in attendance set up a variety of telescopes on the observing field. Please arrive well before dark to avoid splashing attendees with headlight beams.
For details to help get the most out of a night at the HVO and to view a layout of the property, go to this page.
A map to find the observatory.
| Star Party Dates for 2024 | |
|---|---|
April | Monday, April 8 - 11:30 am - 2 pm viewing of the partial solar eclipse through a solar telescope Founders Park - 1510 W Omaha St, Rapid City |
June | Friday, June 14 |
July | Friday, July 12 |
August | *tentative* Custer State Park * NOTE * - a park pass is required for entry into Custer State Park. |
September | Friday, September 6 |
| Themes | |
|---|---|
| Globular Clusters  M13 The Great Globular Cluster | Globular star clusters formed as the galaxy was forming and are aged in billions of years. These pearls of the night sky, over 150 of which orbit the Galactic center, are some of the oldest objects in the Milky Way and increase in concentration toward the Galactic center near Sagittarius and Scorpius. A close collection of stars, globular clusters are often arranged in a sphere that is over 100 light years in diameter and contain thousands to hundreds of thousands of stars. Globular clusters form from molecular clouds, which are clouds of gas and dust that collapse due to gravity and eventually form stars. It's generally believed that when the universe - and thus the Milky Way Galaxy - was very young, hydrogen and helium were essentially the only elements present and, as a result, stars formed during this period were very metal-poor (the term metal is used for any element heavier than helium). The lives of stars vary greatly in length, but as they near the end of their lives they begin to generate elements heavier than helium (i.e. metals) such as lithium, carbon and nitrogen, and either gradually shrug these elements into space as they age (some eventually becoming planetary nebulae), or expel them much more violently if the star goes supernova. Thus, each succeeding generation of stars generally contains a higher proportion of metals leading to the conclusion that metal-poor stars are much older, possibly over 12 billion years old. Globular cluster formation, age and composition continues to be a very active area of research. |
| Open Star Clusters  NGC 1647 - Open Star Cluster | Open star clusters are smaller and younger than globular star clusters. These clusters may contain stars only in the hundreds or thousands. Not being gravitationally bound, the stars will scatter creating clusters of irregular shape and can be found in the plane of our Milky Way galaxy. |
| Constellations  Orion | The constellations have a very long history, and were already part of the historical record in 4000 B.C., but each culture and region sees different patterns in the night sky and many variations have existed over the eons. However, in 1922, the International Astronomical Union defined 88 'modern' constellations and their boundaries, and are what are commonly used by astronomers today. |
| The Moon and Planets  The Moon | Mars is one of the four terrestrial planets, which also includes Mercury, Venus, and Earth, and are so-called because they have similar characteristics such as being small, rocky and slowly rotating. In contrast, Jupiter and Saturn are called gas giants, meaning they're mostly comprised of hydrogen and helium. However, don't be tricked into thinking you could fly through them like the air we breathe! Gravity is at work, and as you descend below the beautiful clouds of Jupiter and Saturn, gravity compresses the gases to the point where they turn into liquids, further towards the center they become metals, and at the core - well, we really don't know what exists at the core because we don't understand the properties of materials at such high temperature and pressure. The moon is estimated to be 4.5 billion years old, and is 'tidally locked' with the Earth, meaning the same side of the moon always faces Earth; the Earth rotates 15 degrees per hour, whereas the moon rotates 12.8 degrees per day. However, due to what's called libration - essentially wobbling of the moon - nearly 60% of the moon surface can be seen over time. The far side of the moon, often incorrectly referred to as the dark side, actually sees as much light as the side facing Earth. This is because the moon is rotating around the Earth, and when you see the full moon - which is when the near side is facing the sun - this means the far side is facing away from the sun, and conversely during a new moon (the near side is facing away from the sun) the far side is facing the sun. |
| Emission/Reflection Nebulae  Rosette Nebula Planetary Nebulae  M57 - The Ring Nebula | Nebula derives from the Latin for 'mist' or 'vapor', and until the early-1900's was generally used to refer to any astronomical object that appeared hazy - including star clusters. In fact, what is now known as the Andromeda Galaxy (M31) can still be found in older textbooks to be presented as the Andromeda Nebula. With Edwin Hubble's discovery in the early 1920's of cepheid variable stars in the Andromeda and Triangulum Nebula, this proved that these distant objects were in fact galaxies, not simply hazy clouds of gas and dust. Nebulae are broken down into two main classifications, dark and bright. Not surprisingly, dark nebulae do not emit light, but instead are clouds of gas and dust (similar to soot) that are silhouetted against a bright background, effectively absorbing or blocking background light. Dark nebulae can easily be seen as seams of darkness weaving throughout the dense star regions of the Milky Way, especially the 'Northern Coalsack' between Cygnus and Cepheus. Bright nebulae, however, are broken down further into four types: emission, reflection, planetary and supernova remnants. Although the long-exposure images of nebulae can be striking, such as those of the Veil, Ring and Crab Nebulae, visually it is often difficult, or impossible, to see nebulae without the aid of special narrowband filters that reduce light pollution and enhance contrast. The Orion Nebula, which rises high in the southern sky during the winter, is one of the few nebulae that can be seen with the naked eye. |
| Double Stars  Albireo | Why are double stars interesting? It's estimated that in our galaxy alone over 50% of stars are actually multiple-star systems, which puts our sun in the minority. Also, through studies of binary systems many properties of stars and star formation have been identified. There are actually many different kinds of binary star systems, but the ones we'll be seeing tonight are either optical doubles, which look like stars that orbit each other but simply just lie along the same line of sight, and visual binaries, which are stars that do truly orbit each other. Alberio, for example, we don't actually know if it's a optical or visual binary. If it is a visual binary, the orbital period (the time it takes for the stars to make one complete orbit of each other) is probably at least 100,000 years! |
| Galaxies  M81 - Bode's Galaxy | Our home, the Milky Way Galaxy, is a barred spiral galaxy, meaning it has the spiral arms most people often associate with galaxies, but it also has a distinct bar of stars emanating from the center of the galaxy. Thought to be at least 100,000 light years in diameter and to have four distinct spiral arms, there is some evidence the Milky Way could actually be as much as 180,000 light years in diameter and have only two arms. Our solar system is approximately 27,000 light years from the galactic center; so, assuming the Milky Way is 100,000 light years in diameter, we're in the suburbs. There are three main types of galaxies - elliptical, spiral and irregular - and several variations of each, with the majority of galaxies being barred spirals. The Milky Way and Andromeda galaxies are on a collision course, and will collide in approximately 4 billion years. |
| Telescopes and Mounts  Observing Field | Several telescopes are setup on the observing field of the Hidden Valley Observatory. Pros and cons of the different telescopes are presented. Telescopes on-hand will include purchased off-the-shelf, homemade, and high-end computer guided. After the presentation, attendees have an opportunity to observe the sky through the variety of telescopes. |