The five nakshatras - Dhanishta ( 3rd and 4th padas ), Satabhishak, P. Bhadrapada, U. Bhadrapada, Revati falling in Kumbha and Meena rasis are collectively called Dhanishta panchakama / Vasu panchakam.
Death in one of these nakshatras causes easy emancipation for the soul of the deceased, but harmful for the kin especially spouse, children and grandchildren. Shastra says there is danger at every step.
Special funeral procedure is performed in such cases. Five human forms made of kusha grass are placed on the dead body at specified places and ahutis offered on them along with placement of gold/silver before the body is submitted to fire. On the thirteenth day special shanti homa is performed for the safety of the kin.
If a person dies on a previous nakshatra and funeral is done during panchakam, then the special funeral vidhi should be followed, but shanti on the thirteenth day need not be done. If the death takes place during panchakam and funeral after panchakam is over, then the special vidhi for funeral need not be followed. Only the shanti on the thirteenth day need not be performed.
For the shanti to be performed, there are some variations as far as the day is concerned like some do it on the 12th day.
The following combinations are even more dangerous -
1. Dhanista + Tuesday + Ekadashi + Vrischika lagna
2. Satabhishak + Wenesday + Dvadashi + Dhanurlagna
3. P.Bhadrapada + Thursday + Trayodashi + Makara lagna
4. U.Bhadrapada + Friday + Chaturdashi + Kumbha lagna
5. Revati + Saturday + Purnima / Amavasya + Meena lagna.
The shanti homa on the 13th day is an elaborate procedure including Mrityunjaya homa and danam.
Similarly, death during tripada nakshatras - Krittika, Punarvasu, U.Phalguni, Vishakha, U.Ashadha, P.Bhadrapada calls for special funeral procedure.