Alert Notice 743: V603 Aql photometry and spectroscopy requested

May 11, 2021

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Campaigns and Observation Reports:
- Novae:

- Spectroscopy:

Please subscribe to these threads if you are participating in the campaign so you can be updated by the astronomer and by HQ. Join in the discussion or ask questions there!

John Myles, Dr. Graeme White, Prof. Bradley Carter (University of Southern Queensland), and David Platz (School of Astronomy & Astrophysics, Queensland) have requested AAVSO observers' assistance in obtaining photometry and spectroscopy of the classical nova V603 Aql (N Aql 1918).

Myles writes: "The purpose of this campaign is to continue the photometric study of this object. The last observational campaign on this object was in 2013...Of particular interest is the behaviour of the photometric period (superhump) associated with this object.  

"These observations will form part of a study of the superhump phenomena exhibited by V603 Aql since it was first found in the system light curves in the early 1980’s. The system displays both negative (shorter than orbital period) and positive (longer than orbital period) superhumps. Studies of this phenomena have shown the prominent photometric period to drift between positive and negative. The confirmation of which period is currently dominant gives insight into the accretion disk mechanics at play and the relationship of the white dwarf star and its donor.

"This [campaign] will also form part of an educational program for the School of Astronomy & Astrophysics in regional Queensland."

This campaign will run from now through the end of June 2021. It may be extended or concluded earlier, depending on when sufficient data have been amassed.  

Photometry in V is requested. Unfiltered observations reduced to a V zeropoint (CV) or DSLR green observations are also welcome. Visual observations are welcome to supplement the light curve. V603 Aql has a V mag of ~11.5-12.2; observations reported to the AAVSO International Database indicate it is currently 11.537 V +/- 0.01 (P. Detterline, Douglassville, PA).

Time series observations with a cadence of 30 seconds are requested. V603 Aql has a photometric period of ~3.5 hrs, and ideal coverage would be a run of 6 hours per night for at least 5 nights (not necessarily sequential). However, any observation runs longer than ~3.5 hours would be useful. Multi-observer datasets would also be useful, and observers may want to coordinate coverage amongst themselves via the forums.

Low resolution spectroscopy is also requested. The goal of the spectroscopy is to capture the orbital period, which is ~3.3 hours. Please submit spectra to the AAVSO Spectroscopic Database (AVSpec), and to John Myles at <>.

Myles indicates that "the initial study is part of an honours project, though co-authorship will be considered for any publications arising from this study."

Coordinates (2000.0): R.A. 18 48 54.64  Decl. +00 35 02.9  (from VSX page for V603 Aql)

Charts: Charts with comparison stars for V603 Aql may be created using the AAVSO Variable Star Plotter (VSP).

Submit observations: Please submit observations using the name V603 AQL to the AAVSO International Database or the AAVSO Spectroscopic Database as appropriate (see below for links).

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen using material provided by John Myles.

Information on submitting observations to the AAVSO may be found at:
 - Photometry/visual observations:
 - Spectroscopy:


An Alert Notice archive is available at the following URL:

Subscribing and Unsubscribing may be done at the following URL:


Please support the AAVSO and its mission -- Join or donate today: