Hari Julian

Hari Julian adalah hitungan hari yang terus menerus sejak permulaan Periode Julian dan terutama digunakan oleh para astronom.

Angka Hari Julian (JDN) adalah bilangan bulat yang ditetapkan untuk keseluruhan hari matahari dalam hari Julian dihitung mulai dari siang waktu Universal, di mana angka 0 hari Julian ditetapkan untuk hari terhitung pada siang tanggal 1 Januari 4713 SM, kalender Julian proleptik (24 November 4714 SM, dalam kalender Gregorian proleptik),[1][2][3] suatu tanggal di mana tiga siklus multitahun mulai (yakni siklus Indiksi, Solar, dan Lunar) dan yang mendahului tanggal mana pun dalam catatan sejarah.[4] Sebagai contoh, angka hari Julian untuk hari yang dimulai pada 12.00 UT pada 1 Januari 2000 adalah 2.451.545.[5]

Tanggal Julian (JD) dari saat mana pun adalah angka hari Julian untuk siang sebelumnya dalam Waktu Universal ditambah fraksi hari sejak saat itu. Tanggal Julian dinyatakan sebagai angka hari Julian dengan tambahan pecahan desimal.[6] Sebagai contoh, Tanggal Julian untuk 00.30.00.0 UT 1 Januari 2013 adalah 2.456.293,520833.[7]

Periode Julian adalah suatu interval kronologis dari 7980 tahun; tahun 1 dari Periode Julian adalah 4713 SM.[8] Ini telah digunakan oleh ahli sejarah sejak pengenalannya tahun 1583 untuk mengkonversi antara berbagai kalender. Tahun kalender Julian 2024 adalah tahun 6737 dari Periode Julian sekarang. Periode Julian berikutnya mulai pada tahun 3268 M.

Lihat juga

• Tahun Julian
• Kalender Julian
• Epos (astronomi)
• Waktu
• Waktu standar
• Milenium ke-5 SM

Referensi

1. Dershowitz & Reingold 2008, 15.
2. Seidelman 2013, 15.
3. "Astronomical Almanac Online" 2016, Glossary, s.v. Julian date. Various timescales may be used with Julian date, such as Terrestrial Time (TT) or Universal Time (UT); in precise work the timescale should be specified.
4. Both of these dates are years of the Christian or Common Era (which has no year 0 between 1 BC and AD 1). Astronomical calculations generally include a year 0, so these dates should be adjusted accordingly (i.e. the year 4713 BC becomes astronomical year number −4712, etc.). In this article, dates before October 15, 1582 are in the (possibly proleptic) Julian calendar and dates on or after October 15, 1582 are in the Gregorian calendar, unless otherwise labelled.
5. McCarthy & Guinot 2013, 91–2
6. "Resolution B1" 1997.
7. US Naval Observatory 2005
8. Astronomical Almanac for the year 2017 p. B4, which states 2017 is year 6730 of the Julian Period.

Daftar pustaka

• Astronomical almanac for the year 2001. (2000). U.S. Nautical Almanac Office and Her Majesty's Nautical Almanac Office. ISBN 978-0-11-772843-1.
• Astronomical almanac for the year 2017. (2016). U.S. Naval Observatory and Her Majesty's Nautical Almanac Office. ISBN 978-0-7077-4166-6.
• Astronomical Almanac Online Diarsipkan 2016-12-24 di Wayback Machine.. (2016). U.S. Nautical Almanac Office and Her Majesty's Nautical Almanac Office.
• Chi, A. R. (December 1979). "A Grouped Binary Time Code for Telemetry and Space Application" Diarsipkan 2020-07-30 di Wayback Machine. (NASA Technical Memorandum 80606). Retrieved from NASA Technical Reports Server April 24, 2015.
• "CS 1063 Introduction to Programming: Explanation of Julian Day Number Calculation." Diarsipkan 2020-12-03 di Wayback Machine. (2011). Computer Science Department, University of Texas at San Antonio.
• Dershowitz, N. & Reingold, E. M. (2008). Calendrical Calculations Diarsipkan 2008-07-12 di Wayback Machine. 3rd ed. Cambridge University Press. ISBN 978-0-521-70238-6.
• Digital Equipment Corporation. Why is Wednesday, November 17, 1858, the base time for VAX/VMS? Diarsipkan 2020-12-14 di Wayback Machine. Modified Julian Day explanation
• Edwards, B B, Smith, John Pye and ben Uziel, Jonathan, The Popular Bible Educator, Vol. 1, Biblical Chronology. Explanation of Technicalities. John Cassell, London 1853.
• Furness, C. E. (1915). An introduction to the study of variable stars. Boston: Houghton-Mifflin. Vassar Semi-Centennial Series.
• HORIZONS System Diarsipkan 2007-03-28 di Wayback Machine.. (April 4, 2013). NASA.
• Ideler, Handbuch der mathematischen und technischen Chronologie, vol. 1, Berlin 1825, available at [1] Diarsipkan 2023-08-15 di Wayback Machine. (in German).
• Information Bulletin No. 81 Diarsipkan 2020-05-11 di Wayback Machine.. (January 1998). International Astronomical Union.
• Julian Date Converter Diarsipkan 2007-10-06 di Wayback Machine. (March 20, 2013). US Naval Observatory. Retrieved September 16, 2013.
• Kempler, Steve. (2011). Day of Year Calendar Diarsipkan 2012-07-05 di Wayback Machine.. Goddard Earth Sciences Data and Information Services Center.
• McCarthy, D. & Guinot, B. (2013). Time. In S. E. Urban & P. K. Seidelmann, eds. Explanatory Supplement to the Astronomical Almanac, 3rd ed. (pp. 76–104). Mill Valley, Calif.: University Science Books. ISBN 978-1-891389-85-6
• Meeus Jean. Astronomical Algorithms (1998), 2nd ed, ISBN 0-943396-61-1
• Moyer, Gordon. (April 1981). "The Origin of the Julian Day System," Sky and Telescope 61 311−313.
• Noerdlinger, P. (April 1995 revised May 1996). Metadata Issues in the EOSDIS Science Data Processing Tools for Time Transformations and Geolocation Diarsipkan 2020-09-28 di Wayback Machine.. NASA Goddard Space Flight Center.
• Ohms, B. G. (1986). Computer processing of dates outside the twentieth century Diarsipkan 2016-01-01 di Wayback Machine.. IBM Systems Journal 25, 244–251. doi:10.1147/sj.252.0244
• Ransom, D. H. Jr. (c. 1988) ASTROCLK Astronomical Clock and Celestial Tracking Program pages 69–143 Diarsipkan 2020-11-06 di Wayback Machine., "Dates and the Gregorian calendar" pages 106–111. Retrieved September 10, 2009.
• "Resolution B1" Diarsipkan 2020-08-26 di Wayback Machine.. (1997). XXIIIrd General Assembly (Kyoto, Japan). International Astronomical Union, p. 7.
• Richards, E. G. (2013). Calendars. In S. E. Urban & P. K. Seidelmann, eds. Explanatory Supplement to the Astronomical Almanac, 3rd ed. (pp. 585–624). Mill Valley, Calif.: University Science Books. ISBN 978-1-891389-85-6
• "SPD Toolkit Time Notes" Diarsipkan 2020-05-11 di Wayback Machine.. (July 21, 2014). In SPD Toolkit / HDF-EOS Diarsipkan 2020-10-28 di Wayback Machine.. NASA.
• Seidelmann, P. Kenneth (ed.) (1992). Explanatory Supplement to the Astronomical Almanac pages 55 & 603–606. University Science Books, ISBN 0-935702-68-7.
• Seidelmann, P. Kenneth. (2013). "Introduction to Positional Astronomy" in Sean Urban and P. Kenneth Seidelmann (eds.) Explanatory supplement to the Astronomical Almanac' (3rd ed.) pp. 1–44. Mill Valley, CA: University Science Books. ISBN 978-1-891389-85-6
• "SOFA Time Scale and Calendar Tools Diarsipkan 2023-03-21 di Wayback Machine.". (2016 June 14). International Astronomical Union.
• Strous, L. (2007) Astronomy Answers: Julian Day Number. Diarsipkan 2012-09-18 di Wayback Machine. Astronomical Institute / Utrecht University.
• Tøndering, Claus. (2014). "The Julian Period" Diarsipkan 2020-10-27 di Wayback Machine. in Frequently Asked Questions about Calendars. author.
• US Naval Observatory. (2005, last updated July 2, 2011). Multiyear Interactive Computer Almanac 1800–2050 (ver. 2.2.2). Richmond VA: Willmann-Bell, ISBN 0-943396-84-0.
• Winkler, M. R. (n. d.). "Modified Julian Date" Diarsipkan 2013-02-14 di Wayback Machine.. US Naval Observatory. Retrieved April 24, 2015.