The Telescope Library has become much more active this year, meeting growing demand with an expanding group of volunteers. The number of loans is already over twice that of last years' peak, and demand continues to grow. At this writing, we have 36 reservations, some of which stretch into October. Interest in Astronomy is also rising, due to the Eclipse on August 21, and we have seen the effects of this in some reservations and questions. More about this next month.Read More
This is third in a series by RCA Member David Horne. This installment will complete the discussion of Earth’s orbital cycles. We can then turn to the Milankovich Theory, its origins and predictions.
There are three basic cycles involved in Earth’s orbit around the sun: eccentricity, orbital precession, and orbital inclination.
The morning of July 11, 1991 our family packed up into the car and headed down the road to find a clear spot from which to view one of the longest total eclipses of the sun. It was on a rural road on the big island of Hawaii and fortunately there was little traffic. After fitting everyone with solar viewing glasses and setting up my tripod holding both my still camera and video camera, the partial eclipse was well under way. However, more clouds were starting to move in from the direction of the centerline path of the eclipse. I panicked and with difficulty herded grumpy kids and all back into the car and drove further down the road to get away from the clouds.Read More
Good weather means star parties and with star parties comes the issue of good light management, so it never hurts to review basic field manners. Stargazers do try valiantly to manage their red lights, but LED manufacturers are making their lights brighter and brighter. Given that with modern technology more is always better, we can assume that these lights are going to continue to get even brighter. I did a check for “dimmable red LED flashlight” on Google and came up with these items: Mini Strong Brightness, Energizer Industrial LED, Military Tactical LED, Bulbrite, Brite LED Headlamp... you get the picture. However, a much better choice would be one of the many dimmable astronomical flashlights that are available. We recommend the Rigel Systems Starlight.Read More
For starters, I didn't quite realize how well Horn Rapids Campground is suited for astronomical observing. It's flat, grassy, easy to get to; has water, electricity, bathrooms and huge open areas. The next day the buses arrived on time for our B Reactor Tour, which was most excellent. That night we moved up to LIGO for a star party we had planned with the local astronomy club. That was the night of the stunning aurora display....Read More
For hundreds of years, people in northern and central Europe had been noticing large, out-of-place boulders that seemed to have been dropped in a field, or popped up from underground. “Erratics”, they came to be called. Legends attributed the boulders to giants, trolls, and the Devil. By the early 1820s many natural history philosophers, scientists, came to focus on ‘ice’ as the likely mechanism of transport. But the source of all the ice was a mystery.
This is second in a series by RCA Member David Horne.Read More
In October 2016, I started planning an astro tour to the southern hemisphere. Why Chile? Because Chile is much closer than Australia, plus I am Latino and fluent in Spanish. Of the two main Chile astro destinations, I decided on the Elqui Valley over San Pedro de Atacama for three main reasons. First, the Elqui Valley is easier to reach, one 45 minute flight from Santiago and then a 57km drive to Vicuna. Second, health reasons. San Pedro is situated at 2407 meters (7900 ft); Elqui Valley is lower at 709 meters (2326 ft). Third, the Elqui Valley has 320 clear nights per year (versus 250 for San Pedro).Read More
The more awareness we “shine” on the importance of dark skies, the more we learn of the detrimental effects to biological organisms. Last June, the American Medical Association (AMA) declared that light at night is harmful to our health. Most recently, researchers studying hamsters found that animals can pass the damaging effects of nighttime light exposure to their offspring. We amateur astronomers know the value of dark skies in satisfying our innate sense of wonder, our passion for science, and our psyches’ fondness for the vast silence of space. But how do we appeal to the folks who haven’t caught the astronomy bug?Read More
The Telescope Library has published a call for volunteers. The details can be found in the Telescope Library board on the Forum, and on the Telescope Library page on the RCA Website. Volunteers are needed to make sure service is responsive and can meet demand, maintain the quality and diversity of our collection, and build the library into a resource for the whole group. In exchange, the library offers training and exposure to the various disciplines required for everything the Library will be doing in the future, and the satisfaction of providing good service to the group.Read More
Is it time to start or renew your magazine subscriptions to Astronomy or Sky and Telescope? Be sure to take advantage of the discounts for RCA club members.
Save a stamp by paying at the next RCA meeting. Just drop off your check/cash (and a mailing label or renewal notice from your magazine) at the Magazine Subscription table. We'll help keep these great magazines coming to your mailbox.
If you can't make it to the RCA meetings, see your other options.Read More
This is the story of the imprint of Earth’s orbital cycles on the climate of our planet. Scientists now believe that certain features of Earth’s orbital motions act as a trigger for Earth’s long-term climate cycles, including the cyclical planet-wide glacier cover, popularly called the “Ice Ages” — and termed by science glacial epochs. Scientists first discovered the glacial cycles in the middle of the 19th Century. But the theory linking the glacial epochs to variations in solar radiation caused by cyclical changes in certain of Earth’s orbital motions, had to wait until the first years of the 20th Century.
This is first in a series by RCA Member David Horne.
Please join members and guests of RCA as we March for Science on April 22 in downtown Portland near the waterfront. Why do we march? That’s simple:
We march in support of scientific research, science education, and dark skies.
If that’s not enough reason to march, then:
MARCH TO CELEBRATE EARTH DAY! MARCH TO CELEBRATE INTERNATIONAL DARK SKY WEEK (April 22-28)!
The outreach team is looking for ~10 volunteers to join us at the fairgrounds on 21 August to support OMSI's event in Salem. All 8000 tickets are sold out, so if you wanted to go - here is your chance!If you don't have a scope, we can provide one for you. If you'd rather do some tabling, you can talk to visitors about RCA, eclipse mechanics, go deep into the Sun, Moon, or anything else astro-related you want to speak on. Please note: You may feel free to pause public viewing from your scope as you need in order to take images, and we will suggest people enjoy the sight. OMSI will be encouraging everyone to view the event in silence (for the most part).Read More
Our Telescope Library collection is stored in space donated by OMSI and TMS (where library items are available each month). This year, conditions are changing at OMSI; with construction planned, our collection will have to reside somewhere else. TMS has been very generous with storage, but we are at our limit for space there.Our first choice is acquiring suitable space, to store the collection. Please contact us if you can help with space. Keep in mind that the fair market value of storage space (as rent) is tax-deductible, as are any donations to fund storage space and transportation, due to our non-profit statusRead More
April 22nd this year is Earth Day. It is also the first day of International Dark Sky Week (April 22 – 28), and the day of the March for Science. The national march in Washington, D.C. is sponsored or supported by over one hundred national science organizations. There will be some four hundred satellite marches around the country, including in Portland. After considered discussion, the Board has voted for RCA to march as an organization in the Portland march on April 22nd: we are marching in support of scientific research and science education, and we will march in support of dark skies.Read More
The trip to the Hanford Laser Interferometer Gravitational-Wave Observatory has been set for Memorial Day Weekend, May 26 – 28, 2017. This trip will include a private tour of LIGO, a a joint star party and eclipse imaging trials with Tri-Cities Astronomy Club, and may also include a tour of Hanford's historic B Reactor of Manhattan Project fame. Registration is now closed. Payment can be made here.Read More
There are two kinds of star parties on our calendar: public star parties promoted by OMSI and private club star parties for RCA members and guests only. Observing season is fast approaching, so let’s take a moment to refresh our memories about star parties and what we can expect at each of them.
Public star parties are all sponsored and promoted by OMSI. This year there are seven OMSI star parties, from March through September. OMSI public star parties are held at two locations on the same nights: Rooster Rock and Stub Stewart State Parks, for the convenience of both our Eastsiders and Westsiders. RCA provides support for these events by coming with our telescopes and sharing views with the public.
Private star parties are RCA club events. They can be found on our calendar and are publicized via our club communication to our members, but are not announced on Facebook or otherwise advertised to the public. The purpose of these events is to have smaller, quieter observing opportunities where members can accomplish their observing or imaging goals, but members are free to invite family and friends to come along.
Clackamas Community College is proud to host a talk by Dr. John B. Herrington, a native of Oklahoma and member of the Chickasaw Nation, selected by NASA in 1996 to become the first registered Indigenous person in space. The lecture will be at Gregory Forum, Thursday March 2, 5:00 p.m., with a book signing and reception beginning at 3:30 p.m.
Commander Herrington is a retired Naval Aviator and test pilot with over 4,700 hours in more than 30 different types of aircraft. He flew as a Mission Specialist for NASA on STS-113 in 2002, logging over 330 hours in space and conducting three spacewalks totaling nearly 20 hours.Read More
Star clusters are objects of great interest to astronomers. The stars in a given open or globular cluster are considered to have been created at the same time from material of the same composition. The stars in a cluster are about the same distance from Earth. This means that any differences in brightness are not due to differences in distance but are due to intrinsic differences in luminosity. These characteristics make it possible to get accurate estimates of age and distance. I set out to see if I could get good estimates for M67 with amateur equipment. M67 is an open cluster in the constellation Cancer. Surprisingly, I was able to get pretty close to accepted values.Read More
We have scheduled another series of astro-imaging classes for beginners. The goal of the series is to give all the information necessary for the beginner to understand what equipment is needed, how to use it, and how to make good pictures with a digital camera. Classes will be held at Clackamas Community College, McLoughlin Hall Room #252, over four weekends (Saturday mornings). The classes will be similar to past classes but we have included a topic on imaging the eclipse. See below for schedule and topics.Read More