V606 Aquilae was a nova, which lit up in the constellation Aquila in 1899. The brightest reported magnitude for this nova was

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

5.5, making it a naked eye object. It was discovered by

Williamina Fleming (15 May 1857 – 21 May 1911) was a Scottish-American astronomer. She was a single mother, hired by the director of the Harvard College Observatory to help in the photographic classification of stellar spectra. She helped develop a common d ...

on a photographic plate (one of the Henry Draper Memorial Photographs) taken on 21 April 1899 at the

Harvard College Observatory The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United St ...

. On the discovery plate, its

photographic magnitude Photographic magnitude ( or ) is a measure of the relative brightness of a star or other astronomical object as imaged on a photographic film emulsion with a camera attached to a telescope. An object's apparent photographic magnitude depends on i ...

was later determined to be 6.75. It was not seen on the plate taken on 1 November 1898, and there were no reported observations of the region around the star during the 171 day interval before Fleming's discovery, so it is possible that the actual maximum of the event was missed. By 27 October 1899 it had faded to 10th magnitude, and on 9 July 1900 Oliver Wendell reported its brightness to be between magnitude 11.5 and 12.0. V606 Aquilae is classified as a "fast nova", because its faded by at least 3 magnitudes in about 65 days. The

light curve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...

showed a steep decline, followed by a period of about 100 days when the light curve plateaued, which caused its light curve to be classified as type P. The nova was "recovered" (meaning the quiescent nova was identified by modern observers) as a magnitude 20.4 object, in 2012 from photometric observations at the

Very Large Telescope The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each with a primary mirror 8.2 m acro ...

. It is now a recurrent

dwarf nova A U Geminorum-type variable star, or dwarf nova (pl. novae) is one of several types of cataclysmic variable star, consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from its companion. Dwa ...

that flares every 270 days and with an amplitude of about 1.5 magnitude.

References

Dwarf novae 181419 IC objects Aquila (constellation) 1899 in science Aquilae, V604 Durchmusterung objects {{var-star-stub