National Capital Astronomers

About NCA

Serving 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. For 2023-24, meetings will be held in-person at the University of Maryland Astronomical Observatory in College Park, Maryland (directions/map) AND online via Zoom (details below). Seating is limited, so we are encouraging folks to attend via Zoom.

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 2023-2024

The meetings for this year will be HYBRID (online via Zoom AND in-person), unless otherwise noted!

With permission of the speakers, most meetings will be recorded. Once available the audio and video will be linked.

Online Meeting Information

National Capital Astronomers will be holding its 2023-2024 meetings online via Zoom and in-person. This year, the Zoom meetings have been set up so that there is no registration required. This is the direct Zoom link, it is the same for everybody for every meeting this year (2022-23). If we have problems with Zoom bombing at a meeting, then the link will be canceled and a new one created that will require registration for subsequent meetings.
As usual, the Zoom room "doors" open at 7pm ET with the actual meeting starting on time at 7:30pm! While you do not need to sign in right at 7pm, please do not wait until 7:35pm!! And since we are not registering folks, it will be important that you have a recognizable name showing so that I can let you in from the virtual waiting room.

Finally, as last year, with the permission of the guestspeakers, we will be recording the meetings.

Join Zoom Meeting: NCA Monthly Zoom

Zoom Etiquette

These guidelines will be updated as needed.

Gravitational Microlensing and the Roman Space Telescope Find the Coolest Planets

Shubham Kanodia, Carnegie Earth & Planets Lab

Next Meeting Date: Saturday, 10 Feb 2024 -- Hybrid

7:30 pm

Abstract: NASA’s next great planet finding mission is the Nancy Grace Roman Space Telescope, which is set for launch in late 2026 or early 2027. One of the major surveys planned for this mission is the Roman Galactic Exoplanet Survey (RGES), which will complete the statistical census of planets that was started by the Kepler Mission, using the gravitational microlensing method. RGES will be sensitive down to sub-Mars masses at wide separations from the host stars. It’s sensitivity overlaps with the widest orbits that Kepler is sensitive to at ~ 1 AU, and extends its sensitivity out to much larger separations and even free-floating planets that have been ejected from orbits around their host stars. I review recent discoveries based on exoplanets found by ground-based observatories, including the recent discovery that free-floating planets may be more frequent that planets orbiting stars. Finally, I preview some of the science that we can expect from RGES.

Bio: David Bennett is a pioneer of the gravitational microlensing method that was first developed to test the possibility that the Milky Way’s dark matter halo could consist of brown dwarfs, but in the mid-1990s he changed his focus to the study of exoplanets with the microlensing method. In 1996, he and his late wife, Sun Hong Rhie showed that microlensing was sensitive to Earth-mass planets, and in 2000, they led the first proposal for a space-based microlensing survey that was eventually approved by the Astro2010 decadal survey as one of two major research efforts for the Nancy Grace Roman Space Telescope. He has led the development of this method since then, and is now the Science PI of the Roman Galactic Exoplanet Survey (RGES) Project Infrastructure Team.

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

Telescope-Making and Mirror-Grinding

Jan 2024

The telescope making, maintenance, and modification workshop with Guy Brandenburg is held in the basement (wood shop) of the Chevy Chase Community Center which is located at the intersection of McKinley Street and Connecticut Avenue, NW, a few blocks inside the DC boundary, on the northeast corner of the intersection. The workshop is open on Tuesdays & Fridays, from 6:00 to 9:00 PM. For information visit Guy's Website. To contact Guy, call 202-635-1860 or Email Guy.

Come See the Stars at Exploring the Sky 2023!

Exploring the Sky is a joint program between the National Capital Astronomers and the National Park Service Rock Creek Park Nature Center and has been run since 1948 at this location, the field at the corner of Glover and Military Roads in the District. There is an adjacent parking lot. It is free and all are welcome who have an interest in observing the heavens. It's not an ideal dark sky location but we can still see solar system objects (even the occasional comet), open and globular clusters and maybe a fuzzy galaxy or two.

This year, as an added feature, you can come one hour early and see a planetarium program in the Nature Center and then come to the field to observe. Also, if the sky is cloudy or it's raining there will be a planetarium program at that one hour earlier time so Exploring the Sky will no longer be canceled! Planetarium programs can be found at: You can also search "astronomy", "dark skies" or call the Nature Center at: (202)-8985-6070.

Questions? Call NCA at 202-635-1860 and leave a message.

Exploring the Sky is a presentation of the National Park Service and National Capital Astronomers.

For NCA information by E-mail or phone

NCA Documents