This is known as the Immaculate Radiance (dri med ‘od gsal). It appears in Longchenpa’s biography, written by Lala Sonam Chodrup (glag bla bsod nams mchog ‘grub), also written as bsod nams chos grub. There is a a paperback version of the this printed by si khron mi rigs dpe skrun khang. On the TBRC site it is: W20468.

Today (January 25th) is the anniversary of his death or parinirvana, according to the Tibetan calendar (18th day of the 12th lunar month). In Tibetan Buddhism, it is the anniversary of a lama’s passing away that is celebrated, more than the annversary of their birth. As Sogyal Rinpoche wrote:

“However consummate our spiritual mastery may be, we are still limited by the body and its karma. But with the physical release of death comes the most marvelous opportunity to fulfil everything we have been striving for in our practice and our life. Even in the case of a supreme master who has reached the highest realization, the ultimate release, called parinirvana, dawns only at death. That is why in the Tibetan tradition we do not celebrate the birthdays of masters; we celebrate their death, their moment of final illumination.”

This year, 2008, marks the 700th anniversary of Longchen Rabjam’s birth in 1308.

Sorry, could you clarify this a little? It is his birthday and the anniversary of what?