What is Gayatri Sadhana? How it is different from Gayatri mantra japa? What is its significance? Is it supposed to be performed only by Brahmins? Are the results different in each case? Who needs to perform Gayatri Sadhana? Also is this sadhana done as per vedic or non-vedic principles?
I prefer to start the answer to this question by quoting from the the Gospel of Sri Ramakrishna :
Gayatri merges with Omkar (or Pranava) . In that stage, one can do japa of only Om. Ultimately Pranava dissolves in samadhi.
So this is the process and the goal of gayatri japa. The process of getting samadhi state and being illumined is the major objective of the Gayatri japa-sadhana.
By the way, the same did happen in the life of Sri Sitaramdas Omkarnath. Whenever He wanted to do the Gayatri Japa, He could just utter OM and then invariably got immersed in samadhi.
When Ishan Chandra Mukhopadhyay, a great devotee and aspirant wished to do the purascharana of Gayatri, Sri Ramakrishna said :
In the age of kali, the vedic path does not work. Now the Tantrik way is advised. Can not you do the purascharana in the Tantrik way?
So here He makes it clear that the Gayatri worship can be done in the Tantrik way also.
The Gayatri Mantra is a part of the Sukla-yajurvediya Swasti-vachana(Adhyaya 36, Reference- Stavakusumanjali, Udbodhan, page 41). It can therefore be chanted by the three varnas only, who have been initiated properly by Upanayana or the sacred thread. Non-trivarnas including women do not have the right to chant Gayatri. However, Tantra has also included this Gayatri (Pranatoshini-Tantra,kanda 3,pari:4, Niruttara-Tantra, parva 3, Reference-Sastramulak Bharatiya Shaktisadhana ,Upendrakumar Das, RMIC, vol.2, page 887), but its use is restricted to the initiated Trivarnas only.
By Gayatri, we mean this Vedic Mantra, which is also known as the Savitri -Mantra. However, in the Taittriya-Aranyaka, there are Gayatri Mantras of Rudra, Ganesha, Nandi, Kartikeya,Garuda, Brahmaa, Vishnu,Narasimha,Surya, Agni and Durga. There are some other Gayatris like the Hansa Gayatri as well. You can find most of them in the answer to the question:Where can I find the Gayatri mantra commonly used?
Tantra gives us Gayatri Mantras of various deities like Mother Kali and the other nine Mahavidyas, and of Durga (slightly different from the Vedic one).
Any Gayatri is a part of the Vedic or the Tantrik sandhya. For all iniated people of all varnas, doing sandhya regularly is a must : it is a Nitya-Karma.The Tantra-initiated Tri-varnas have first to do the Vedic sandhya that includes the Vedic gayatri(Savitri) and then Tantrik sndhya that icludes the Tantrik Gayatri of the Ishtadaevata.Sri Ramakrishna by the way advised to focus only on the Gayatri Japa if one does not get time to do the sandhya by the way.
Focusing on the Savitri Mantra alone can be termed as the Gayatri Sadhana. As Sri Ramakrishna mentioned, the Gayatri sadhana may include Gayatri purascharana also.Generally there are five parts in purascharana (called Panchaanga-Purascharana) : japa, homa, tarpana, abhiseka and vipra-bhojana. But there is provision of dasa(Ten)-anga purascharana too. Purascharanas are all Tantrik ways and Tantra allows purascharana of the Savitri mantra.The dtails are available in different scriptures and has to be learned only from an able Guru.
The goal of any sadhana can be sakama (for attaining something specific as boon from the Deity being invoked) or nishkama (for attaining the Ultimate Knowledge through samadhi).
Sri Sri Ramdas Kathiababa got the direct vision of Devi Gayatri by doing Gayatri-japa. Devi appeared before Him and asked Him to take any boon He desired. Kathiababa wanted Her grace alone. He later got direct vision of His Ishta-Devata Sri Krishna.The latter has been mentioned as 'Bhagavad-darshana' in His biography by the way
Gayatri-Baba of Chakrata was also siddha in the Gayatri-Mantra. He used to have direct communications with Goddess Gayatri.
In these days, Gayatri(Savitri)-Sadhana is being recommended by some individuals or organisations (I can name Om Swami and Gayatri Parivar for example). You could easily find the links on internet. But the traditional views of the scriptures and saints do not allow such sadhana, as the Gayatri (Savitri) sadhana is reserved by the holy scriptures for the initiated sacred threaded tri-varnas only.
(Reference : 1. Sri Sri Ramakrishna-Kathamrita, compiled by M, Udbodhan edition 2. Sri Sri Ramdas Kathiababa by Sri Sri Santadas Kathiababa, (the pdf version of this bengali book I downloaded online : http://dspace.wbpublibnet.gov.in:8080/jspui/handle/10689/32387 3. Sri Sri Omkarnath Rachanavali, Mahamilan Math, Vol.6 4.Nava nava rupe eso praane by Kinkar Vittal Ramanuj Jeyar, Mahamilan Math, Kolkata.
Usually by mantra sadhana we mean the Purascharana of that particular mantra. So, Gayatri sadhana involves Gayatri Purascharana, which is accomplished by 24-lakhs of Japa (1 lakh multiplied by the number of letters the mantra is made of). Then the 1/10 th of that number, Homa, 1/10th of Homa, Tarpana and similarly Marjana, Bhojana.
There is a whole chapter entirely dedicated to Gayatri Purascharana in Devi Bhagavatam which starts with:
1-55. Nârâyana said :-- Now I shall speak of the Gâyatrî-puras’charanam. Hear. By its performance all the desires are obtained and all the sins are destroyed.
This is the 21st chapter of the 11th Book of the Purana.
As is usual, the places considered sacred for mantra Purascharana are the sacred hill-tops, river banks, forests, cow-pens etc. If Japa is to be done in one's own house, then considerations like Kurma Chakra Nirupanam are to be duly done.
On the tops of mountains, on the banks of the rivers, on the roots of Bel trees, on the edges of tanks, within the enclosures of the cows (cow-stalls), in temples, on the root of As’vattha trees, in gardens, in the Tulasî groves, in the Punya Ksetrams (holy places), before one’s Guru, or wherever the mind feels exalted and cheerful, and gets strength, the Puras’charanam if performed, lead to a speedy success.
Other suitable places for the performance are Shiva-alayas (temples of Lord Shiva) and various other holy Kshetras.
The Puras’charanam of Gâyatrî is repeating this twenty four lakh times (i.e., as many lakh times as there are syllables in the Gâyatrî). But, according to Vis’vâmitra, repeating thirty two lakh times is the Puras’charanam of Gâyatrî. As the body becomes useless when the soul leaves the body, so the mantra without Puras’charanam is useless.
Take the permission of the Brâhmanas and begin the Puras’charanam. Where the S’iva Lingam exists, facing west, or in any S’iva temple, commence repeating the mantra. The other S’iva Ksettrams are :-- Kâs’î, Kedâra, Mahâ Kâla, S’rî Ksettra, and Tryamvakam. These five are the Great Ksettrams, known widely on this earth, for the fructification and the siddhis of the Mantras. At all other places than these, the Karma Chakra is to be drawn according to the principles of the Tantra. And then they will be fit for Puras’charanam. The number of times that the Puras’charanam (the repeating of the mantra) is done on the first day, the same number is to be continued every day until completion; not greater nor less than that and also no intermission or stoppage should occur in the interval
Nandi Mukha Sraddhas, Prayaschittas, Pitri Tarpanam etc are to be done prior to starting the act, in order to make the body sufficiently pure. During the whole process, the aspirant must maintain celibacy, sleep on floor and consume only foods considered as Havishyanna.
And, some days, months, Nakshtras etc are considered not suitable for the performance.
The Puras’charanam is prohibited in the months of Jyaistha, Âsâdha, Pausa and Mala (dirty) months. Also on Tuesday, Saturday; in the Vyatîpâta and Vaidhriti Yogas; also in Astamî (eighth), Navamî (ninth), Sasthî (sixth), Chaturthî (fourth) Trayodas’î (thirteenth), Chaturdasî (fourteenth) and Amâvâsyâ (New Moon), Tithis (lunar days); in the evening twilight and in the night; while the star Bharanî, Krittikâ, Ârdrâ, As’lesâ, Jyesthâ, Dhanisthâ, S’ravanâ, or the Janma naksatra (Birth time star) is with the Moon; while the signs Mesa, Karkata, Tulâ, Kumbha, and Makara are the Lagnas (signs in the ascendant). When the moon and the start are auspicious, especially in the bright fortnight, the Puras’charanam performed, gives the Mantra Siddhi. First of all repeat Svasti vâchan and perform duly the Nândi mukha S’raddha and give food and clothing to the Brâhmanas.
Some more useful details are found in the following verses:
The repeating of the Mantra is to be commenced in the morning and should be done up to midday. While doing this, the mind is to be kept free from other subjects, and it is to be kept pure; one is to meditate on one’s own Deity and on the meaning of the mantra and one should be particularly careful that no inaccuracies nor omissions should occur in the Gâyatrî, Chhandas and in the repetition of the Mantra. One tenth of the total number of Puras’charanams that are repeated is to be used for the Homa purpose. The Charu is to be prepared with ghee, til, the Bel leaves, flowers, jaya grain, honey and sugar; all mixed, are to be offered as oblations to the fire in the Homa. Then the success in the Mantra comes (i.e., mantra siddhi is obtained or the Mantra becomes manifested)
Actually a Guru directs the disciple on how to perform this Sadhana and it can not be learnt from books. Without Guru's permission, Purascharana is never done too.