Perhitungan Awal Ramadhan (Pantai Gebang - Bangkalan)

HISAB AWAL BULAN RAMADHAN 1432 H

SISTEM EPHEMERIS

Markaz : Pantai Gebang-Bangkalan (-6° 59’ 8” LS ; 112° 47’ 12.9” BT ; Tinggi tempat : 5 m)

Oleh : ARIF ROCHMAN, S.Ag M.Si (Kankemenag Bangkalan)

Ijtima’ Akhir bulan Sya’ban 1432 H

-          FIB[1]  terkecil  terjadi pada tanggal 30 Juli  2011 pk. 18.00 GMT = 0.00093

-          ELM[2]  pk.20.00 GMT = 127° 14’ 20”

-          ALB[3]  pk.20.00 GMT = 126° 51’ 31”

-          Sabaq Mthari (SM) perjam;      ELM pk 20.00 GMT      = 127° 14’ 20”

                                                        ELM pk 21.00 GMT             = 127° 16’ 43” –

                                                                           SM       =      0° 2’  23”

-          Sabaq Bulan (SB) perjam;    ALB pk.20.00 GMT          = 126° 51’ 31”

                                                     ALB pk 21.00 GMT = 127° 26’ 53” –

                                                                              SB     =     0° 35’ 22”

- Saat Ijtima’ [4] = Jam FIB + ((ELM – ALB)/(SB – SM)) + 7 jam

                         = 20 + ((127° 14’ 20”-  126° 51’ 31”)/(  0° 35’ 22” - 0° 2’ 23”)) + 7

                         = 25 ^jam  41 ^mnt   30.35^dtk  WIB atau  01 ^jam  41 ^mnt   30.35^dtk  WIB  tanggal 31 Juli 2011

HISAB TERBENAM MATAHARI

- Equation of time (e)[5]  pk 11.00 GMT             =  -0^jam 06^mnt 24^dtk

- Deklinasi (d)[6]  pk 11.00 GMT                          = 18° 17’ 15”

- Semi Diameter (SD)[7] mthri pk 11.00 GMT   = 0° 15’ 45.29”

- Refraksi (Pembelokan cahaya mthri)                               =  0° 34.5’ (lihat table Refraksi)

- Dip (Kerendahan ufuk) à 1.76 Ö5 / 60         = 0° 3’ 56.13”

- KWD (Koreksi Waktu Daerah)                        = (15 x 7 - 112° 47’ 12.9”)/15 = -0° 31’ 9”

- Tinggi (h)[8]  matahari ; 0 – SD – Refr – Dip   = -0° 54’ 11.42”

        Sudut Waktu (t)[9] Matahari :        Cos t      = -tan j  tan d + sin h / cos j  / cos d

                                                                                = -tan -6° 59’ 8” tan 18° 17’ 15” + sin  -0° 54’ 11.42” /cos  -6° 59’ 8”                                                                      .                                                                           / cos 18° 17’ 15”

                                                                                = 0° 01’ 25.56”

                                                                        t       = 88° 38’ 17.31”     

        

      Saat terbenam matahari ( Gh° )                 = t/15+12 – e +  Kwd

                                                                                = 88° 38’ 17.31” / 15 +12 – (-0^jam 06^mnt 24^dtk) + (-0° 31’ 9”)

                                                                                = 17^jam 29^mnt 48.15^dtk  WIB ----à 10^Jam 29^mnt 48.15^dtk GMT

AR (Right Ascension)[10]  Matahari dan Bulan saat terbenam

(dengan Interpolasi ---à A -(A-B)C/1        pk. 10^Jam 29^mnt 48.15^dtk GMT  è C = 0^Jam 29^mnt 48.15^dtk GMT)

* AR Matahari pk. 10.00 GMT                            =  130° 17’  24”

  AR Matahari pk. 11.00 GMT                            =  130° 19’ 50”

  AR Matahari  pk 10^Jam 29^mnt 48.15^dtk GMT    =  130° 18’ 36.5”

*AR Bulan pk. 10.00 GMT                                  =  137° 32’  13”

 AR Bulan pk. 11.00 GMT                                   =  138° 06’  31”

 AR Bulan pk. 10^Jam 29^mnt 48.15^dtk GMT           =  137° 49’  15.2”

Sudut Waktu (t) Bulan         = AR Matahari – AR Bulan + t Matahari

                                                =  130° 18’  36.5” - 137° 49’  15.2” +  88° 38’ 17.31”     

                                     t          =   81° 07’  38.61”

Deklinasi (d )Bulan  ;  d Bulan pk. 10.00 GMT                                =  11° 58’  54”

                                   d Bulan pk. 11.00 GMT                    =  11° 46’  33”

Deklinasi (d ) Bulan pk. 10^Jam 29^mnt 48.15^dtk GMT         =  11° 52’ 45.94”

Tinggi / Irtifa’ Hakiki (h) Hilal[11]

                Sin h       =  Sin  j  Sin d  + Cos j  Cos d   Cos t

                                =  Sin -6° 59’ 8”” Sin 11° 52’ 45.94” + Cos -6° 59’ 8” Cos 11° 52’ 45.94” Cos 81° 07’  38.61”

                                =    0°  7’  29.2”

                      h        =   7° 10’  4.52”

Tinggi / Irtifa’ Marr’I ( h’ ) HILAL  ---à    h’     =  h – Parallaks + SD + Refraksi + Dip

                                                                         h     =  7° 10’ 4.52”

                                                        Parallaks[12]    = 0° 59’  22.53” -  => Horz. Parlk pk 10 & pk 11 diinterpolasi x cos h

                                                                                   6° 10’  41.99”

                                                                SD          =  0° 16’ 10.71” +  è hasil dari interpolasi

                                                                                    6°  26’ 52.7”

                                                                Refrk      =  0°  07,15’          +

                                                                                    6° 34’  1.7”

                                                                Dip          =  0° 3’ 56.13”   +

                                                                h’         =  6° 37’ 57.83”

MUKUTS / Lama Hilal diatas ufuk (LHU°) sejak matahari tenggelam --à h’/15   =>  6° 37’ 57.83” / 15

                                                                                                                                                                    =  0 ^jam 26 ^mnt   31.86 ^dtk

Saat Hilal terbenam ( HG°)              = Gh° + LHU°

                                                                = 17^jam 29^mnt 48.15^dtk  +  0 ^jam 26 ^mnt  31.86 ^dtk

                                                = 17 ^jam 56 ^mnt   20.01 ^dtk

Azimut[13]   Matahari dan Bulan saat terbenam

* Azimut Matahari                                = tan ^-1 (1/(-sin j  / tan t + cos j  tan d / sin t ))

                                                = tan ^-1 (1/(-sin -6° 59’ 8” / tan 88° 38’ 17.31”+ cos -6° 59’ 8” tan 18°17’15”/ sin 88°       .                                              38’ 17.31”))

                                                =  71° 41’ 6.31”  (dari titik utara ke arah barat) = 18° 18’ 53.69” BU

* Azimut Bulan                     =  tan ^-1 (1/(-sin j  / tan t + cos j  tan d / sin t ))

                                                = tan ^-1 (1/( -sin -6° 59’ 8”/ tan 81° 07’  38.61”+cos -6° 59’ 8” tan 11° 52’ 45.94” / sin 81° .                                             07’  38.61”))

                                                = 77° 01’  49.16” (dari titik utara ke arah barat)  = 12° 58’  10.84”  BU

POSISI HILAL       =  Azimut Matahari – Azimut Bulan

                                = 71° 41’ 6.31” - 77° 01’  49.16”

                                = -5° 20’ 42.85”  (diselatan Matahari)

PENAMPAKAN HILAL :  miring ke selatan

LUAS CAHAYA HILAL (CH)              : FIB pk. 10.00 GMT & FIB pk 11.00 GMT diinterpolasi

                                               = 0.006777-(0.006777-0.007538)x 0° 29’ 48.15”/1