janmakundli men sat grahon ke sath do chaya grah rahu evan ketu ko bhi unke gochar ke anusar sthapit kiya jata hai. vaidik yug men rahu grah nahin tha, balki ek rakshas tha. pauranik yug men us rakshas ke do bhag ho gaye. samudra manthan ke pashchat mile amrit ko devtaon men bantte samay dhokhe se amritpan karne ke pashchat rakshas ka sir bhagvan shri hari vishnu dvara sudarshan chakra dvara dhar se alag ho gaya. sir-rahu men tatha dhar ketu men amar ho gaya. pauranik gathaane men rahu-ketu sarp ke sir aur punch mane gaye. rahu ke kal tatha ketu ko sarp bhi mana gaya hai. rahu aur ketu donon hi papagrah hain. rahu striling hai. adrra, svati, shatbhisha nakshatron par uska shasan hai.
3, 6, 11 bhavon men ise achcha mante hain. ramchritmanas men tulsidas ji ne likha hai- ‘‘ajhun det dukh ravi shashih sir aveshshit rahu’’ uchcharashi mithun, nichrashi dhanu hai. iski jati mlechch evan akriti dirgh tatha disha nairritya hai. rahu ka ratn gomed hai. brihatparashar horashastra ke anusar pancham bhav men rahu ho aur us par mangal ki drishti ho athva pancham bhav men mangal ki rashi ho to purvajanm ke sarpashap ke karan is janm men aisi kundli vale jatak ke putra nahin hote hain. yadi hote hain to bhi mrityu ko prapt ho jate hain. rahu ketu ki uchchata v nichta ke vishay men jyotishiyon men bara matbhed hai.
‘‘rahostu kanyaka gehan mithun svachchaman samritam kanya rahu grah prokt rahuchch mithun samritam rahanichin dhanuah prokt ketoah saptam mevch’’ rahu kanya rashi men svagrihi tatha mithun men uchch tatha dhanu men nich mana jata hai evan iski mul trikon rashi kark mani gai hai. parantu kai jyotish shastri rahu ko vrishabh rashi men uchch evan ketu vrishchik men uchch tatha iski mul trikon kunbh aur priya rashi mithun mani hai. rahostu vrishabh ketoah vrishchike tunbh sanjitam. mul trikon kunbhchan priya mithun uchchate.. brihatparashar hora men rahu ka uchch vrish, ketu ka uchch vrishchik, rahu mul trikon kark, ketu ka mul trikon mithun aur dhanu, rahu ka svagrih kanya v ketu ka svagrih min mana hai.
is tarah rahu ke svagrih, uchch, mul trikon aur nich ke bare men jyotish sarva sammat nahin hai. rahu ko brahmaji ne grah hone ka vardan to diya parantu chaya jaise ghumti hai (vakra gati) vaise hi ye grah ghumte hain. islie rahu ke parinam akasmik hote hain. kai jyotishi rahu-ketu ko grah hi nahin mante hain. rahu-ketu grahan men surya aur chandra ke vimardak hain, atah prabal pap grah hain. parantu akash men inka apna binb nahin hai, atah ye svatantra falkarak nahin hain. rahu navam sthan men ho aur navmesh yadi balvan ho to achcha falkarak hota hai. visheshrup se budh navmesh ho to achanak bhagya chamkta hai, rahu, shani ke sath ho to dhan hani yog kar deta hai. yadi janmakundli men chandrama evan rahu ka paraspar sanbandh ho to, vyakti ki mansik sthiti ko asamanya banata hai.
yadi yah sanbandh shubh ho, to jatak jivan men apratyashit safltaen prapt karta hai v yadi chandrama rahu ke sath dushit sthiti men ho to jatak ko jivan men anek utar-charhav, asthirta evan dhokhe ki sthitiyon ka samna karna parta hai. chandrama yadi apni nich rashi vrishchik men ho to tatha us par rahu ki drishti ho to jatak man se pareshan rahta hai. chandrama yadi ashtm bhav men rahu ke prabhav men ho to, usse trikon men rahu ka gochar jatak ko lanbi yatraon ke lie vivash kar deta hai.
yadi chandrama dvadash bhav men ho tatha rahu se prabhavit ho to, usse trikon men rahu ka gochar dhan hani karta hai. kisi karanavash dhan ka apavyay hota hai ya jatak thagi ka shikar ho jata hai. rahu ki mahadsha jatak ke lie vishesh mahatvapurn hoti hai. yadi rahu ke nakshatron men bali evan yogkaran grah sthit hane to aise jatak ke lie rahu ki dasha-mahadsha ativ shubh faldayak hoti hai.