How to Interpret the Observation Date Format from the Minor Planet Center (MPC)

-- Anura Guruge | June 6, 2020

Question:

Can you please help me decode ‘decimal’ time as used by the MPC etc. What I mean is: 2020-05-27.54100.

I am fine till I get to the decimal point. Then I am lost & baffled & worse still just can’t find a link on Google that will explain it to I.

Please help. Just send me a link or two. I am good at reading. Thanks. SMILE.

-- Anura Guruge

Answer:

I believe that the observation date format which includes a decimal on the day value indicates fractions of a day. For example in the date 2020-05-27.54100, the part past the decimal is interpreted as 0.54100*24 hours = 12.984 hours = 12 hours and 0.984*60 minutes = 12 hours 59.04 minutes = 12 hours 59 minutes 0.04*60 seconds = 12 hours 59 minutes 2.4 seconds. Therefore, your example date would be 12 hours 59 minutes 2.4 seconds on May 27 2020.

-- Jeff Mangum

Facebook

Twitter

The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
	Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.
	The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."
	AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.