* Astronomy

In ancient Roman religion, the Epulum Jovis was a ritual feast offered to Jove on the Ides of September 
http://en.wikipedia.org/wiki/Epulum_Jovis

The Temple of Jupiter Optimus Maximus was dedicated on September 13, the year of the Roman Republic, c. 509 BC
http://en.wikipedia.org/wiki/Temple_of_Jupiter_Optimus_Maximus

A partial solar eclipse will occur on September 13, 2015.
http://en.wikipedia.org/wiki/Solar_eclipse_of_September_13,_2015

A partial solar eclipse will occur on September 13, 2080
http://en.wikipedia.org/wiki/Solar_eclipse_of_September_13,_2080

Solar Eclipse of 1178 September 13
http://eclipse.gsfc.nasa.gov/SEsearch/SEsearchmap.php?Ecl=11780913

On 13 September 1922, a controversial high temperature of 57.8°C (136°F) was recorded in Al 'Aziziyah
http://en.wikipedia.org/wiki/Al_Aziziyah

The first ascent of Piz Bernina was made on 13 September 1850
http://en.wikipedia.org/wiki/Piz_Bernina#Climbing_history

Mary (c. 1894-September 13, 1916) was a five-ton Asian elephant who performed in the Sparks World Famous Shows circus.
http://en.wikipedia.org/wiki/Mary_(elephant)

The Goiânia accident was a radioactive contamination accident that occurred on September 13, 1987
http://en.wikipedia.org/wiki/Goi%C3%A2nia_accident

The Battle of Baltimore was fought between British and American forces in the War of 1812.
http://en.wikipedia.org/wiki/Battle_of_Baltimore

The National Confectioners Association (NCA) celebrates International Chocolate Day on Sept. 13.  (birthday of Milton S. Hershey)
http://en.wikipedia.org/wiki/Milton_S._Hershey

Programmers' Day is celebrated on the 256th (hexadecimal 100th, or the 2^8th) day of each year
http://en.wikipedia.org/wiki/Programmers%27_Day

Aviation authorities saw 14-bis, also known as Oiseau de proie, fly on the 13 September 1906
http://en.wikipedia.org/wiki/14-bis

China's first sounding rocket T-7 was first launch on 13 September 1960
http://en.wikipedia.org/wiki/T-7_%28rocket%29

The Solwind P78-1 satellite was destroyed by an ASM-135 ASAT missile on 13 September 1985
http://en.wikipedia.org/wiki/ASM-135_ASAT

On September 13, 2008, NASA's Swift satellite detected GRB 080913
http://astronomy.activeboard.com/t20727292/grb-080913/

About 13 September 2011, SN 2011fe reached its maximum brightness of apparent magnitude +9.9
http://en.wikipedia.org/wiki/SN_2011fe

In 1994, the Ulysses space probe explored the southern solar polar regions
http://en.wikipedia.org/wiki/Ulysses_probe#Solar_southern_polar_regions

On September 13 1959 Luna 2 successfully impacted with the lunar surface east of Mare Imbrium
http://en.wikipedia.org/wiki/Luna_2

On September 13, 1999, Moonbase Alpha was blasted out of Earth's orbit
http://en.wikipedia.org/wiki/Moonbase_Alpha_(Space:_1999)

Manhattan Project: the reactor, first slug, was powered up on 13 September 1944
http://en.wikipedia.org/wiki/Manhattan_Project#Hanford_reactors

On September 13, 2008 Category 2 Hurricane Ike hit Galveston 
http://en.wikipedia.org/wiki/Hurricane_Ike

On 13 September 1253, an entry in the astronomical report Koryo-sa indicated that Mars had hidden a star
http://astronomy.activeboard.com/t54944014/mars-planetary-conjunction-1253/


Asteroid (12) Victoria was discovered by J. R. Hind on September 13, 1850
http://en.wikipedia.org/wiki/12_Victoria

Asteroid (104) Klymene was discovered by J. C. Watson on September 13, 1868
http://en.wikipedia.org/wiki/104_Klymene

Asteroid (436) Patricia was discovered by Max Wolf and A. Schwassmann on September 13, 1898 in Heidelberg.
http://en.wikipedia.org/wiki/436_Patricia

Eris and Dysnomia were officially named by the International Astronomical Union on September 13, 2006
http://en.wikipedia.org/wiki/Xena:_Warrior_Princess_in_popular_culture#Astronomy