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National Capital Astronomers

About NCA

NCA logoServing science and society since 1937. The National Capital Astronomers (NCA) is a non-profit, membership supported, volunteer run, public service corporation dedicated to advancing space technology, astronomy, and related sciences through information, participation, and inspiration, via research, lectures and presentations, publications, expeditions, tours, public interpretation, and education. NCA is the astronomy affiliate of the Washington Academy of Sciences. We are also members of the Astronomical League, in fact NCA members helped form the Astronomical League a long time ago.

NCA has for many years published a monthly newsletter called Star Dust that is available for members. Besides announcement of coming NCA meetings and a calendar of monthly events Star Dust contains reviews of past meeting and articles on current astronomical events.

NCA is a very unusual astronomy organization. All are welcome to join. Everyone who looks up to the sky with wonder is an astronomer and welcomed by NCA. You do not have to own a telescope, but if you do own one that is fine, too. You do not have to be deeply knowledgeable in astronomy , but if you are knowledgeable in astronomy that is fine, too. You do not have to have a degree, but if you do that is fine, too. WE ARE THE MOST DIVERSE local ASTRONOMY CLUB anywhere. Come to our meetings and you will find this out. WE REALLY MEAN THIS!

Our Meetings

Monthly Meetings with Educational Presentations are Free and Open to the Public

NCA has regular monthly meetings September through June on the second Saturday of the month.

Public transportation: Directions/maps to the UMD Observatory
Inclement weather: In case of severe weather (tornado/snow/impassable roads), a notice will be placed on the Observatory Website on the day of the meeting. (Be sure to refresh/reload the page to make sure you are seeing an updated page.)

Meeting Schedule for 2015-2016

Most meetings will be held at the University of Maryland Astronomical Observatory in College Park, Maryland (directions/map).

Next Meeting Date: Saturday, 08 Oct, 2016

7:30 pm at the University of Maryland Observatory on Metzerott Road.

How to "See" Supermassive Black Holes

Speaker: Erin Kara, UMD, GSFC

Abstract: The material spiraling towards the event horizon of a black hole is subject to the strongest gravitational distortions in the universe, so studying these extreme environments can help us understand how gravity behaves when it is pushed to its limits. As material (mainly gas and dust) plunges into the black hole, a significant fraction its gravitational potential energy is released into the surrounding environments, which heats up the remaining infalling material. This material becomes so hot and energetic that it radiates light, much of which is in the X-ray band. So while the common colloquialism is that black holes are `black', they are, in fact, the most luminous objects in the universe because of the energetic material around them. It is impossible to simply take a picture of the spacetime around a black hole because the region is too small and too far away. Instead, astronomers develop sophisticated ways of analyzing the limited data available. In this talk, I will discuss a new and innovative technique that was discovered just 5 years ago. The technique is called X-ray reverberation, and it allows us to measure distances of tens of light seconds around black holes that are hundreds of millions of light years away. Just as sound waves reverberate in a large auditorium, X-ray light reverberates in the inflowing material. Since we know the speed of light, we can relate this reverberation time delay to a distance, which helps us determine the size and shape of the material spiraling towards the event horizon. Understanding these environments close to the event horizon is helping us to understand how black holes grow, and how they feed energy back into their surrounding environments.

Bio: Dr. Erin Kara is a Hubble Postdoctoral Fellow and a Joint Space-Science Institute Fellow, working at the University of Maryland and NASA Goddard Space Flight Center. Her research is on understanding the inner accretion flows around black holes and other compact objects using X-ray observations. She works with a new technique called X-ray reverberation mapping, that probes the flow's geometry and dynamics by measuring the echoes produced when light is scattered by the inner accretion flow. Dr. Kara completed her graduate studies at the University of Cambridge in the UK before moving to Maryland.

Weather-permitting, there will be observing through the telescopes after the meeting for members and guests.


Join Us for Dinner Before the Meeting

Telescope-Making and Mirror-Grinding

Telescope-making and mirror-making classes with Guy Brandenburg at the Chevy Chase Community Center, at the intersection of  McKinley Street and Connecticut Avenue, NW, a few blocks inside the DC  boundary, on the northeast corner of the intersection, in the basement  (wood shop), on Fridays, from 6:30 to 9:30 PM. For information visit Guy's Website  To contact Guy, use this phone #: 202-262-4274 or Email Guy.

Come See the Stars at Exploring the Sky 2016!

Exploring the Sky is an informal program that for over sixty years has offered monthly opportunities for anyone in the Washington area to see the stars and planets through telescopes from a location within the District of Columbia.
Sessions are held in Rock Creek Park once each month on a Saturday night from April through November, starting shortly after sunset. We meet in the field just south of the intersection of Military and Glover Roads NW, near the Nature Center. A parking lot is located next to the field.
Beginners (including children) and experienced stargazers are all welcome-and it's free!
Questions? Call the Nature center at (202) 895-6070 or check: Exploring the Sky @ Rock Creek. Download the flier!

Date Time Targets of Interest
2 Apr 8:30pm
7 May 9:00pm
4 Jun 9:00pm
9 Jul 9:00pm
6 Aug 8:30pm
3 Sep 8:00pm
1 Oct 7:30pm
5 Nov 7:00pm
Exploring the Sky is a presentation of the National Park Service and National Capital Astronomers.

Star Parties

For NCA information by E-mail or phone

NCA Documents

NCA constitution and by-laws current as of August 28, 2005 they need some changes so we can continue to be a healthy organization.
NCA constitution and by-laws revision as of October 25, 2005 proposal.

HOME | Telescope Making Workshops | Exploring the Sky | Contact Info | Star Dust Archive | Links

Updated by E. Warner on 19 Sep 2016.