Gravitational Wave Detection Lectures
By Donna Pursley and Leo Taylor
ASNH Members Donna Pursley, Mike Zarick, and Leo Taylor have attended two lectures on gravitational waves.
1. March 2016 at BAR in New Haven by Dr. Louise Edwards
The first lecture started with the causes of gravitational waves, why they could travel distances, and how weak the received signal was. One cause of gravitational waves is the merging of two black holes, which takes less than 1 second. The resulting mass is measurably less than the sum of the parts with the missing matter released as energy. The initial swirling movements result in a wave envelope that rises gradually and disappears suddenly. Though the wave is not sound, it is at audio frequency. Dr. Edwards played a sound file of the “PING” of the first ever gravitational wave detected. We also saw us graphs of the predicted waves and how close the actual wave matched.
We decided to attend a second lecture due to the great advances in detection technology over almost two years.
2. January 2018 at the Westport Astronomical Society by Dr. Jillian Bellovary, “Gravitational Waves: Ripples in Space-Time”
Jillian Bellovary is a terrific speaker! She had a few slides and animations and would talk about them with such enthusiasm. She was able to answer every question. If she didn’t know the answer, she had an amusing reason why not.
She explained what gravitational waves are and why it is a good idea to detect them. This is a way to learn about space without using light. Using LIGO (Laser Interferometer Gravitational-Wave Observatory), astronomers have detected merging black holes. The two black holes spun around closer and faster until they collided.
There are 3 LIGOs now. They are located in Hanford Washington, Livingston Louisiana, and Italy (called VIRGO). With three, scientists are better able to pinpoint where the merger took place.
The LIGO detectors in the US were in operation for the initial detections. Early searches produced no results. The LIGOs were upgraded with new equipment that would increase sensitivity. As luck would have it, shortly after the reconfigured LIGOs were turned on both detected a wave! The time between arrivals was short but compatible with the predictions. Several months were spent checking the results to determine if it was real. The third site in Italy came on line and it added triangulation to better locate the source of the gravitational wave.
By the time of the second lecture there were five detections, including the first pair of neutron stars colliding to produce a gravitational wave. This burst had more energy and included visible light which arrived after the gravitational wave. It was visible a few days allowing telescopes to photograph the flash. The first day it was bright blue then dim red.
There are plans to build a much bigger LIGO called LISA (Laser Interferometer Space Antenna), using three satellites that will follow the earth in its orbit. LISA will be able to detect smaller mergers and other events that cause ripples in spacetime.
Together the two lectures provided us with an understanding of the physics involved in detection and an awe for the technology needed to capture the waves.
ASNH Loans Telescope to E. C. Scranton Memorial Library in Madison, Connecticut
By Laurie Averill
On January 17, 2018, ASNH loaned a beginner telescope to the E. C. Scranton Memorial Library in Madison, Connecticut. This is the second telescope loaned to a public library by the club. The first is on loan to the James Blackstone Memorial Library in Branford, Connecticut. The goal of the program is to develop interest in astronomy and strengthen ties with communities that have supported the club’s public outreach events. Madison hosts ASNH public astronomical observing sessions at the annual Madison Moon Walk and at Bauer Farm. Through the use of Young’s Pond Park, Branford helps the club connect with astronomy enthusiasts through monthly observing events in the spring and fall. Loaning a beginner telescope to community members through their public libraries provides people with another way to learn about astronomy.
Funds to purchase the telescope kits were donated to ASNH by club members. The kits include Orion StarBlast 4.5 Astro Reflector Telescope, Orion Soft Case, Celestron 8-24mm Zoom Telescope Eyepiece – 1.25 Inch, National Audubon Society Pocket Guide: Constellations, telescope manual, 3-V batteries, and replacement bolts. The kit specifications were originally developed by the Marc Stowbridge of the Education Outreach Committee of the New Hampshire Astronomical Society that currently has more than 100 kits on loan to libraries throughout New Hampshire. It has served as a model for programs throughout the US. The telescopes are adapted by club members to make them easier to use and loan by attaching the lens caps and eyepiece, and replacing the collimation screws with bolts.
ASNH members offered several training sessions to library staff, teens, and then the general community at the libraries before loaning the telescopes. The sessions covered how to use the telescope, some interesting things to view during the current season, and upcoming ASNH events. Community members borrow a scope for one week, and at both libraries there are waiting lists. Club members are available for telescope maintenance and to offer additional training sessions that highlight telescope use and interesting seasonal astronomical sights.
Astronomy Links
Submitted by Ray Kaville
Constellation Guide
Information for observers on telescope targets organized by constellation, plus a lot of other useful information.
Mars Odyssey Observes Martian Moons
Both moons were captured in the same frames of a short video. Their irregular shapes are seen in detail.