Of all the objects an amateur astronomer can discover visually, the most difficult is a nova. Comet hunters have it easy — it's comparatively simple to find a diffuse, slow-moving glow among fixed pinpoints of light. But a nova — a thermonuclear blast that occurs on the surface of a white-dwarf star in a binary-star system — is merely a "new" star among hundreds of other background stars.

The explosion occurs when gas transfers onto the white dwarf from its cooler, larger companion. The gas causes the dwarf's surface layers to ignite explosively and shine brightly. In a typical nova, the white dwarf can brighten up to 10 magnitudes before fading from view. But the majority of novae are found in the most densely populated region of our heavens, the Milky Way. And spotting a new star among such a crowded background is a challenge. That's why prolific visual nova discoverers are such a rare breed — and why Alfredo J. S. Pereira of Cabo da Roca, Portugal, stands out among the crowd.

Pereira systematically sweeps the sky with 9 x 34 and 14 x 100 binoculars. His discovery credits include three novae found in a span of 21 months. His last two discoveries are especially notable in that they were made 11 days apart in the same constellation less than 3° from one another. On August 26th Pereira found Nova Sagittarii 2001 No. 2 (V4739 Sagittarii) shining at magnitude 7.6 about 45 arcminutes east of Delta (d) Sagittarii; then on September 5th he discovered Nova Sagittarii 2001 No. 3 (V4740 Sagittarii) at magnitude 7.0, about 2° west-southwest of Delta. The feat is unprecedented — many nova hunters spend years between discoveries.