WORTH NOTING ON TV

* FRIDAY

Robert F. Kennedy documentary (NBC, 9-11 p.m.): It's 25 years, believe it or not, since the tragic event in a hotel kitchen that so shocked the nation in 1968: the gunning down of Robert Kennedy while he was a leading contender for the Democratic presidential nomination. With this much elapsed time for perspective, "Robert F. Kennedy: The Man, the Myth and the Memories" takes a long look at the life and career of the person who was the heir apparent, in the minds of many, to the John F. Kennedy legacy. B ut the program also looks at Kennedy the father and husband, using clips from the Kennedy family's private library not seen before. Anecdotes from friends and colleagues also help paint the portrait.

The Coronation (PBS, 10-11 p.m.): This year marks four decades since the coronation of Elizabeth II as Queen of England, a ceremony of memorable pomp and splendor. Though she's paying taxes these days and reading publicity she doubtless hoped she'd never see, she maintains a heroically stiff upper lip - and with more humor and grace than many give her credit for. Both color and black-and-white footage from British Pathe News recreate the pageantry and offer an image of a country engrossed with royal ritu als.

Unseen Treasures (The Learning Channel, 8-9 p.m.): Museums have been doing all right for themselves on TV lately. Lectures and other museum events will be an important component of "Horizons," a cable channel being launched by PBS later this year. Meanwhile, in this six-part miniseries, TV cameras are being turned on the often amazing stuff found in the "hidden recesses" of famous museums. During the two episodes aired as a two-part premiere, host Adrienne Meltzer goes to Washington's Museum of American History, where she finds Gen. George Custer's uniform and other evocative items. The second episode visits the Royal Armouries at the Tower of London and shows us, among other things, armor, guns, and swords. (The remaining programs air on consecutive Friday nights.)

Please check local listings for all programs, especially those on PBS.