Howard Astronomical League - Meetings

January 19

February 16

Annual treasurer's report & members astrophotos plus special guest speaker.

Speaker: NASA Astrophysicist, Dr. Ira Thorpe

Title: The 100 Year History of Gravity Waves, and the LISA/LISA Pathfinder Missions 

Abstract: In September 2015, nearly a century after Albert Einstein’s publication of the theory of General Relativity, the Laser Interferometer Gravitational-wave Observatory (LIGO) instruments detected gravitational waves produced by colliding black holes in the distant universe. While that feat marked the end of a nearly six-decade quest to make the first direct detection of gravitational waves, it marks the beginning of a new an exciting field of astronomy that will use gravity, not light, to explore and understand our universe and the strange phenomena that inhabit it. Just as electromagnetic astronomers have developed a suite of instruments to cover a wide range of that spectrum, gravitational wave astronomers are developing instruments that are sensitive to different frequencies of gravitational waves. One of the most promising bands, expected to be rich in both number and variety of sources, is the milliHertz band, which is only accessible to a space-based observatory. 

In 2015, the European Space Agency launched LISA Pathfinder, a technology demonstrator for the Laser Interferometer Space Antenna (LISA) concept. LISA Pathfinder’s primary objective is to demonstrate that a test mass can be placed in near-perfect free-fall and that it’s acceleration can be precisely measured using a laser interferometer. In this talk Dr. Thorpe will describe LISA Pathfinder, its key technologies, NASA’s role, and the preliminary results to date. He will also provide a look forward to the prospects for realizing LISA and the tremendous science output that it will achieve.

March 16

April 20

In addition to the recurring meeting elements, the talk for May is:

Eclipse 2017: Through the Eyes of NASA
The August 21, 2017 eclipse will be the first time a total solar eclipse has traversed the Continental US since June 8th, 1918. This talk will outline NASA’s science education  plans, unique science, and show how scientists and the public can get involved.

Speaker: Lou Mayo
Lou Mayo is a planetary astronomer working for ADNET Systems at the NASA Goddard Space Flight Center. He is Program Manager for NASA's 2017 Eclipse Science Education Program and Heliophysics Education Consortium and professor of astronomy at Marymount University.

Guest Speaker HAL Member and UMBC Professor Bob Provine:

The Perception of Color in Astronomical Objects

The human eye has been displaced as the sensor of choice of astronomers, but astronomers and other physical scientists still refer to red and blue light as a shorthand for long and short wavelengths and make fallacious assumptions about the nature of the perceptual world, neglecting that there are differences between the physical world and our perception of it. Data from neuroscience indicate we descendants of hunter-gathers are not ideal astrophysicists. Issues of color are also significant for amateur astronomers trying to describe and understand what they see. What is responsible for the color the point sources of stars and the distributed sources of nebula? Why do the stellar
pairing double star Alberio look especially blue and gold? Why does the companion of Aldebaran look green, a unique hue for stars? Why does color disappear from landscapes after sunset? 

In describing these and other phenomena, Bob will demonstrate that color is not a property of the physical universe, but is generated by the brain to provide an additional dimension of image contrast. There is no red, blue, or green in the cosmos. Building on Land's Retinex Theory, he will provide evidence that color must involve more than simply wavelength perception, otherwise there would be no stability of color under different conditions of illumination. Perceived color is the result of ratios of reflectances of wavelengths off different surfaces, not of specific wavelengths. he will also provide demonstrations of these phenomena. Although his data reflect accepted color theory, they are startling when encountered for the first time."

Guest Speaker: Roopesh Ojha, NASA Astrophysicist

Dr Roopesh Ojha works for the Fermi Gamma-ray Space telescope at the NASA Goddard Space Flight Center. His current research is focused on multi-wavelength and multi-messenger observations of active galactic nuclei and the design of the next generation of high energy space observatories.

TALK TITLE: Astronomy on Ice

ABSTRACT: The South Pole is a hotbed of astronomical research. Despite being a somewhat hostile environment for humans, it provides unique advantages for many kinds of telescopes making possible observations that would otherwise only be possible from space or not at all. It is also a fantastic place to study atmospheric phenomenon that are rarely seen elsewhere on Earth. The speaker "wintered over" with a sub-millimeter telescope and will provide glimpses of science and life at the bottom of the world where daily life is about as "otherworldly"as you can get without leaving our home planet.

Guest Speaker: Dr Bindu Rani, NASA Post Doctoral Fellow at Goddard Space Flight Center

Talk Title: Wobbling jets in active super-massive black holes

Abstract: Powered by accretion onto super-massive black holes (masses up to 10 billion Solar mass), active galactic nuclei (AGN) are strong emitters of electromagnetic radiation over a range spanning more than 20 decades in energy. About 1 in 10 AGN convert a substantial fraction of accretion energy into highly collimated and relativistic outflows of energetic plasma called "JETS". Many AGN jets do wobble, i.e., show temporal variations in their direction on parsec scales. While the causes of "jet wobbling" are not agreed upon, it is a powerful  probe of energy extraction from super-massive black holes.