Beginning in late September, a continuing series of minor to moderate geomagnetic storms have triggered aurorae along the northern tier of U.S states and may have affected some public power systems operating at high northern latitudes. These events were caused by high-speed material streaming out from areas on the sun known as coronal holes. We can expect more of the same as more coronal holes rotate into position to send high-speed solar wind particles toward our planet.

The recent increase in geomagnetic activity offers a taste of things to come as the Sun approaches the maximum of its 11-year sunspot cycle. As sunspot numbers mount, coronal mass ejections and solar wind disturbances will trigger more and more geomagnetic storms. In extreme cases, these storms can induce electric currents in the earth and oceans that interfere with electric power transmission equipment.

The extra ultraviolet (UV) and X-ray radiation created by magnetic fields around sunspots also cause the Earth's atmosphere to heat up and expand. This creates added drag in the area where low-earth orbit satellites and the Space Shuttle orbit. Solar flares and energetic particle events further complicate matters by interrupting satellite and short-wave radio communications. It's not all bad news, though. The increased levels of solar activity will likely trigger dazzling auroral displays at mid-latitudes. Sky watchers in the continental U.S. will be treated to sights normally reserved for residents of higher latitudes. Another piece of good news is that increased atmospheric drag at solar maximum acts as a scavenger and helps clean out space debris from low-Earth orbit.

When will the solar maximum actually take place? Recent work by David Hathaway, a solar physicist at the Marshall Space Flight Center, and his collaborators indicate that the solar activity will peak around the middle of the year 2000.

"Our predictions have consistently targeted 2000 as the beginning of solar maximum,"says Hathaway, "but the latest numbers suggest that the peak sunspot count in 2000 will be a bit lower than expected. The projected peak is comparable to, but lower than the peaks of the last two maxima (in 1989 and 1978). That would put all three of the recent sunspot maxima in the same class -- above average compared to all the sunspot cycles since the mid 1700's."

A common misconception about the solar maximum is that it is a brief event that happens on a particular day, as reported in one recent news story that warned of a solar catastrophe on January 1, 2000. Not so, says Hathaway.

Above: By combining data about geomagnetic activity during the previous solar cycle with sunspot counts for the current cycle, David Hathaway and collaborators are able to predict when the next sunspot maximum will occur. According to their results, the sunspot number - and other forms of solar activity - will peak beginning mid-2000. The dotted lines above and below the solid curve line indicate the prediction curve's range of error.

"The sunspot maximum is usually a broad peak. There is a two or three year period when activity is quite high. I wouldn't say that we're really in the solar maximum yet. I expect solar activity to be highest in 2000 and 2001, and then in 2002 it may decline back to where we are now in October 1999."

"The effects we've been experiencing for the past few weeks are relatively minor geomagnetic disturbances caused by the solar wind flowing out of coronal holes. A coronal hole is something you see in x-ray pictures of the sun where the corona appears dark. In contrast, bright spots in the x-ray image tend to overlie sunspot groups where hot gas is bottled up in magnetic fields that rise up out of one sunspot and bend back to reconnect at another spot nearby."

"The magnetic fields around coronal holes are different," he continued. "Instead of looping back to reconnect on the sun's surface, these magnetic fields are essentially open. They go way out into the solar system and no one knows exactly where they reconnect. These open field lines allow high-speed solar wind particles to escape."

In fact, the solar wind streams off of the Sun in all directions, not just from coronal holes. But the wind speed is high (800 km/s) over coronal holes and much lower (300 to 400 km/s) elsewhere. The higher pressure streams from coronal holes buffet the Earth's magnetic field and can produce geomagnetic activity.

For more information about space weather and current solar activity, including official alerts, warnings, and forecasts, please see NOAA's Space Environment Center web site at http://www.sec.noaa.gov/.

Story from NASA Space Science News http://science.nasa.gov on
October 14, 1999.
Author: Dr. Tony Phillips.
Credit: Marshall Space Flight Center, Space Science Laboratory.

Tuesday, December 14 at 7:00 p.m. is the first of two episodes on ETV on the Space Station program. "The Journey Begins" questions why we need a space station and how it began. The following Tuesday, also at 7:00 p.m. is the second episode titled "The Next Step". It lays out plans for the future.

If you missed the following programs we have them in our library. Wednesday, November 10 there was a feast of programs hosted by Timothy Ferris on Mississippi ETV.

The first was a two part series Life Beyond Earth. The first hour, "Are We Alone" , examined the origin of life on Earth and looks at the possibility that it might exist on other worlds as well. The second hour, "Is Anybody Listening", was about the strategies being employed to communicate with fellow travelers among the stars - SETI.

Following these was a 15 year old program Ferris produced in 1985 titled The Creation of the Universe. This marvelous 90 minute program examines what the universe is made of and how it got to be the way it is. It is the best program on cosmology your editor has ever seen. I highly recommend it to those who want to know what science says about the physical beginning and end of the universe. (Caveat: remember this program is 15 years old, and some of what it says has been outmoded)

NOTE: We currently have over 1,000 programs in our video library for member and educational use. If you have programs in your library or see any on satellite or cable that you think might add to the usefulness of our library, please let us know.

The search for planets around other stars has taken a new turn. Scientists have found what they think is a planet about three times the mass of Jupiter orbiting around a binary star system for the first time. Since most of the stars in the neighborhood of the Sun are binary or multiple stars, this discovery increases the chances that most stars have planets. All of the 20 or so previously discovered planets have been in orbits around single stars, although some of these stars are in binary systems.

The researchers used a technique called gravitational lensing. In this project , called the Microlensing Planet Search (MPS), the gravity of a nearby object brightens the light of a distant star as the foreground object passes in front of it. In this particular event, the pattern of brightness appeared too complex to be produced by a single star lens.

The story will be in the November 4 issue of Nature or online at http://bustard.phys.nd.edu/MPS

The new dome is in place with the 6 inch D&G refractor inside.
Builders Dale Jones and Andy Doty stand in front of their master-
piece. We can't decide whether to call it the Armadillo dome or not,
but at least it had a police escort up the hill. Dale insists
that the puckers on the aluminum panels give it "character"

New Time Service

The Naval Observatory now has an online way to put atomic time on your computer.

http://www.time.gov

This site gives the official US time and is maintained by the National Institute of Standards. This clock will be within one ten-millionth of a second of the correct Coordinated Universal Time.

discount hotels in Odense A comet discovered last month may become bright enough to be seen by the naked eye by the middle of next year, although it it is not likely to be as brilliant as the two show stoppers earlier this decade.

Comet C/1999 S4 LINEAR was discovered by the LINEAR automated telescope in New Mexico as part of an asteroid and comet search program. It was first thought to be an asteroid, but later observations show a faint fuzzy coma.

Orbital calculations show it to have a parabolic orbit that will pass about 70 million miles from the Sun in July 2000. It is currently magnitude 16, but it is expected to brighten to magnitude 3 or 4 and be visible to the naked eye in the northwest after sunset in late July.

The Hubble space telescope has been out of service since November 13 when a fourth gyro failed and the scope was put into safe mode. The scheduled third servicing mission has been moved up. Liftoff at Kennedy Space Center is now scheduled for 12:13 p.m. EST on Dec. 11. An international crew will replace all 6 gyros, a fine guidance sensor, a transmitter, and an advanced computer with 20 times the speed and 6 times the memory of the original computer.

It's that time of year again. If the mailing label on the envelope which you received this newsletter says EXP 12/99 then it's time to re-up. Dues for the year 2000 are $15.00. Make checks out to the Rainwater Astronomical Association and mail them to the address below.

If you also want to take advantage of the club discount subscription rate to Sky & Telescope magazine, send us a check for $29.95 payable to Sky Publishing. This is $10 off the regular subscription price, so club dues are almost a freebie. If you are already subscribed to S&T through the club, and are a current member, send renewals to the club secretary, Craig, at the address below.

Other benefits of joining/renewing include membership in the Astronomical League, their quarterly national newsletter, The Reflector, discounts to any Astronomy-related books through the AL's Book Service, and observing programs with which you can receive certificates and recognition in The Reflector. If you want to find out more e-mail Craig at chodges@astronomers.org or visit http://www.astroleague.org

If you've ever wondered how to get started learning astronomy, here's a great way. Watch a video course presented by one of the best teachers in the country. Superstar Teachers is a company that records lectures by great teachers. Dr. J. D. Biggers and Dr. Elbert White of Corinth are donating such an astronomy course to our library. If you want to reserve this course for personal or school use, call or e-mail your request.

This year we've set a new record for the number of group tours and programs presented. We passed the 200 mark in November. Thanks to everyone who's visited us and supported our work!