Visibility of Luna and Lunar Crescent

The coftcctions for Abe@don md Nuradon de done in dc sanc way as St p4
and Slep-5 b€fore. Fi@lly te conveBion to rhc equaronat @ordinates dd then b
horizonlal coordiDr.s is als done lhc sme way 6 ws done ror fte Moon.
2.? RISING AND SETTINC
For the d.refti@tion ofprecise rihings of rhc setrnE or nsing of& obFcl one
requircs pEcis c.l€stial coordinales of $eF objech 6i lh€ insht of1he occunine ofrhe
phehomem However! these insranh dre the points ofime that we rcqlic ro find our so
rhar a process oasuccessive appoxinadon is needcd lo ahv€ al lhee dhes. Such an
iterarive plocess is nec€ssry b4au$ rhe objccis under con$dsaion (lbe Sun Md the
Moon) significantly changc thei position relalive to the ixed cel€sriat sDhere durihg m
i.terval around ha a ddy. The whols process shns sm m esehare ror the ritoc of
'ransn ofthe objed (ove.lhe locatneridian) wbich lben reads ro,nlial esrinars for de
holrmghs ar th. appoxihare line ofrhe rising orselling or thc objer Th€e aB in facr
the csimares for rhe tocat sidereal rinres ofdc phenonena. rrco these esfnales of rtE
sdceal rimcsoflhe eveors lhe unilecat hean slarrimeardlheh lhe toql lihescan be
cakuhted. ths. fist approximarions fo! lhe ransii rbe nsihg ed rbe sedne are
obtajned usinglhc cetestirtcoordjnars ofthe obj(r evaluard ar Oh. Ur. ar any poinr or
rhe glob€ and ao! any otrhe evenrs under considecdon lhis nomeir ((]i, Ul oay be m
cail.r or a tater nom€nr. This is the rson lhar the mrfial catcularions are onlv
rppo\imaro cdlcutduon fo.hcle appo\,dar. ,t.., "t
,h. .,.",. ,h. ."i..;;:.
coordnats of thc objecr hNc to bc catcutaled asain and wholc.atculalions henLion€d
above !!€ repealed for bekr esrimates, The details of rh€e catculalions arc describ.d in
(he followinS p@sraphs.
, . Forrhe sh. rhccompnaaon. &e simptes conp@ rornore tor lhe Moon. the
,(o nme or hNir ot rhe Sun can be hirra ) coturdered ar t2-,tocsl rzonc, rime
wnecas for the Moon n dEily vdi*. Th6 Unileisat Tihe or loql tuir is simply 12
Zl wheE ZT (ene ne) is posirive for the east lons,udq ed nesarivc for Resr
58