V606 Aquilae

Lore & Background

V606 Aquilae was discovered by Williamina Fleming on a photographic plate taken on 21 April 1899 at the Harvard College Observatory. The plate was one of the Henry Draper Memorial Photographs. Its photographic magnitude on that plate was later determined to be 6.75. The brightest reported magnitude for the nova was apparent magnitude 5.5, making it a naked-eye object. It was not seen on a plate taken on 1 November 1898, and no observations of the region were reported during the 171-day interval before discovery, so the actual maximum may have been missed.

By 27 October 1899 it had faded to 10th magnitude, and on 9 July 1900 Oliver Wendell reported its brightness between magnitude 11.5 and 12.0. The nova is classified as a 'fast nova' because it faded by at least 3 magnitudes in about 65 days. Its light curve showed a steep decline followed by a plateau of about 100 days, leading to a type P classification.

In 2012, the nova was 'recovered' as a magnitude 20.4 object from photometric observations at the Very Large Telescope. It is now identified as a recurrent dwarf nova that flares every 270 days with an amplitude of about 1.5 magnitude.

Reader's Guide

V606 Aquilae is significant as a historical nova whose light curve characteristics—a steep decline followed by a 100-day plateau—led to its classification as type P, a subtype of fast nova. Its discovery by Williamina Fleming on a Harvard photographic plate highlights the role of early photographic surveys in variable star astronomy. The uncertainty about whether the actual maximum was missed, due to a 171-day gap in observations, underscores the limitations of early detection methods. The recovery of the quiescent nova in 2012 at magnitude 20.4 using the Very Large Telescope demonstrates the power of modern instrumentation to identify and study old novae long after their outbursts. Its subsequent reclassification as a recurrent dwarf nova, flaring every 270 days with an amplitude of about 1.5 magnitude, adds a new dimension to its legacy, showing that some novae can transition into a different type of variable star behavior. This object thus bridges 19th-century discovery with 21st-century astrophysical understanding.

Did You Know?

• Its brightest reported magnitude was 5.5, making it visible to the naked eye.
• In 2012 it was recovered as a magnitude 20.4 object and is now a recurrent dwarf nova flaring every 270 days.