20 Million Observations

[1]On Feburary 19, 2011 the number of observations in the AAVSO International Database [2] surpassed the 20 million mark. It is fitting that this milestone was achieved during our 100th anniversary [3]. Below is some information about the achievement.

• Announcement by Arne Henden to the AAVSO Discussion Group
  [4]
• Official Press Release Issued by the AAVSO:
  • English [5]
  • Spanish [6]

The 20 millionth observation itself was submitted by Josch Hambsch of Belgium. Josch has provided the following story about his background and the observation:

My name is Dr. Franz-Josef Hambsch, but I prefer my nickname Josch. I am in astronomy since more than 35 years. For more than 10 years I have a permanent observatory in my backyard at my home in Belgium. Since then I am into CCD imaging,
for many years doing pretty pictures. However this is rather difficult under my light polluted environment and the weather conditions here in Belgium. Being a scientist also the scientific part of amateur astronomy got my attention. All started with a bright Gamma Ray burst in 2003 (GRB030329) from that moment onwards I started observing variable stars with my CCD camera. The first interest was mainly on RR Lyrae stars, since their variation is nicely visible within a night’s observations (I still need to submit those observations to AAVSO). In Belgium we have a very active group of variable star observers (Werkgroep voor veranderlijke sterren (WVS)), which during the years evolved from mainly visual observations towards nowadays more CCD imaging. As you can imagine, I am member of this organization. I am also member of the German organization of variable star observers (Bundesdeutsche Arbeitsgemeinschaft für Veränderliche Sterne (BAV)) and the French GEOS (Groupe Européen d'Observation Stellaire) group mainly observing RR Lyrae stars. I have now completely changed my interest in astronomy towards variable star observations. Within these organizations I concentrate towards understudied RR Lyrae stars, High Amplitude Delta Scuti (HADS) stars and cataclysmic variables (CV, observations of those are sent to the VSNET and CBA networks). I joined the AAVSO in 2009 after participation in the 98th AAVSO spring meeting in Big Bear, California. I also share with the AAVSO one of the AAVSO-net telescope (W30) as I have contributed the CCD camera, filter wheel and filters for this scope. As, I get lots of data from this scope and my own scopes in my backyard, I am always behind sending data to the AAVSO, so that is why the 20 millionth observation was on GV And from October, 12, 2010. This star seems to show a small Blazhko effect and there are not many observations in the GEOS database (http://rr-lyr.ast.obs-mip.fr/dbrr/dbrr-V1.0_0.php [7]) after 2002. With the submission during the last weekend, I also have submitted more than 150000 CCD observations to the AAVSO database (except GRB030329 (18 observations in 2003)) from 2006 onwards. Many more to come. Last but not least, I would like to thank Patrick Wils for his continued search towards interesting stars to observe, Tom Krajci for his dedication to the AAVSOnet and Pierre de Ponthiere for his software which enabled me to submit the observations in the extended AAVSO format.

Every one of the first 19,999,999 observations is just as important as this one. One can't get to 20 million without standing on the shoulders of those that came before. In fact, over the past century about 7,500 observers have submitted observations to the database.

An informal contest was held to predict the date the milestone would officially be surpassed. We received 14 submissions. The winner was Chris Watson, who successfully predicted February 19. Second place went to Tim Crawford (March 2) and third place to Mike Simonsen (March 3).

As of this writing (Feb. 22, 2011), the database has 20,017,126 observations. Below is their breakdown by type. (These are unofficial, back-of-the-envelope tallies.)

Here are the top ten observers, by number of total observations, for each type:

Top 10 Visual Observers

Obs     ObsCode Name                    Country         Affiliation1
463295  JA      ALBERT JONES            NEW ZEALAND     RASNZ-VSS 
292710  OB      M. DANIEL OVERBEEK      SOUTH AFRICA    ASSA 
208629  LX      WAYNE LOWDER            USA             AAVSO 
187050  BRJ     JOHN BORTLE             USA      
182978  SRX     ROD STUBBINGS           AUSTRALIA       RASNZ-VSS 
173786  PYG     GARY POYNER             UK       
172543  VED     PAUL VEDRENNE           FRANCE          AFOEV 
170663  OV      EDWARD ORAVEC           USA             AAVSO 
166059  CR      THOMAS CRAGG            AUSTRALIA       RASNZ-VSS 
161745  DK      REGINALD DE KOCK                        AAVSO 

List of all visual observers. [11]
Top 10 CCD Observers

486479  TRE     RAY TOMLIN              USA             AAVSO 
423624  JM      Robert James            USA             AAVSO 
375784  MXT     CHRISTOPHER MIDDLETON   SOUTH AFRICA    ASSA 
310557  DKS     SHAWN DVORAK            USA      
266074  SAH     GERARD SAMOLYK          USA             AAVSO 
240979  SBL     BART STAELS             BELGIUM         VVS 
174555  MLF     LIBERT MONARD           SOUTH AFRICA    ASSA 
168280  SX      LEROY SNYDER            USA             AAVSO 
155644  VMT     TONNY VANMUNSTER        BELGIUM         VVS 
153609  COO     LEWIS COOK              USA             AAVSO 

List of all CCD observers. [12]
Top 10 PEP Observers

14340   APOG    Auckland Photometric Observers Group   New Zealand     AAVSO 
8231    THR     RAYMOND THOMPSON                       CANADA          AAVSO 
5564    CSL     LEOPOLDO CELIS S.                      CHILE           AAVSO 
4243    LKA     KENNETH LUEDEKE                        USA             AAVSO 
3238    WJM     JAMES WOOD                             US              AAVSO 
2987    JRW     RAYMOND JONES                          SOUTH AFRICA    ASSA 
2741    STQ     NICK STOIKIDIS                         GREECE          AAVSO 
2407    HPO     Jeffrey HOPKINS                        USA      
2133    MBE     BRIAN MCCANDLESS                       USA             AAVSO 
1806    DSG     SERGIO DALLAPORTA                      ITALY           UAI 

List of all PEP observers.
[13]

AAVSO staff archivist Mike Saladyga helped assemble the following bits of historical information about the database:

• The first published compilation of AAVSO observations was in the December 1911 issue of Popular Astronomy. It comprised 198 observations of 69 stars from the earliest 7 members (two of them women: Anne S. Young and Helen M. Swartz) of the newly-founded AAVSO.
• By 1913-1914, the AAVSO had a total of 28,327 observations; the annual total for that year was 15,128.
• Average annual total observations during the 1940s was about 41,000, with a peak year at about 56,000 in 1947. The low point of that decade, 1943, saw only about 32,000 observations that year.
• In 1954-1955, the AAVSO received 64,990 observations made by 35 observers in 19 countries.
• In 1963-1964, the AAVSO received 83,599 observations from 303 observers in 18 countries.
• In 1970-1971, more than 125,000 observations were received at AAVSO HQ. There were more than 600 requests for data from professional astronomers and others.
• In 2003, about 500,000 observations were received.
• By 2006, the annual total received was well over 1 million.
• In 1954, when the AAVSO had accumulated less than 40 years of variable star observations, nearly everyone was saying that long period variable stars were well-understood, further observations were of little use, and the AAVSO ought to be disbanded. Since then hundreds of papers have been published in professional astronomical journals about LPVs and it continues to be a vibrant field, with dedicated sessions at most meetings of the American Astronomical Society.

Here's to 20 million more!

¹ The affiliation is that which was provided by the observer.

The illustration was created by Nico Camargo [14] and is available for use under the Creative Commons Attribution-Attribution-Share Alike 3.0 License [15]. Please attribute it to "Nico Comargo and the AAVSO" where possible. A 300dpi version is available by clicking here. [16]