Alert Notice 415: Recurrent Nova U Scorpii in outburst

January 28, 2010
Object: U SCO
Coordinates: R.A. 16h 22m 30.80s Dec. -17o 52' 43.0" (2000.0)
The recurrent nova U Sco is in outburst at magnitude V=8.05 on 2010 January 28.4385 UT (JD 2455224.9385) according to observations by Barbara G. Harris, New Smyrna Beach, FL, USA. The outburst was confirmed by Shawn Dvorak, Clermont, FL, USA, who estimated it at V~8.8 at Jan 28.4743 (2455224.9743). Prior to outburst, U Scorpii was measured at V=18.2 on Jan 27.4501 (Harris), and estimated at m(vis) < 16.5 on January 27.6271 (Mike Linnolt, Hoolehua, HI, USA).
According to observations in the AAVSO International Database, the last outburst of U Sco occurred on JD 2451235 (1999 February 25), when the star reached visual magnitude 7.5. U Sco is an extremely fast nova, and will reach maximum and decline by one magnitude within one day.
Visual, CCD, and PEP observations are urgently requested, including unfiltered CCD time series. Please obtain S/N of at least 50 for all instrumental photometry. Observers are asked to use filters when performing single-measure photometry, but unfiltered time series is also requested beginning immediately and continuing for the next month.
The AAVSO has been participating in a campaign on U Sco by request of Dr. Bradley Schaefer (LSU; see AAVSO Alert Notice 367, January 22, 2008). This nova outburst will be observed by several ground- and space-based observatories world-wide, and your observations are urgently requested to provide the overall, long-term optical light curve of U Sco.
Charts for U Sco are available via VSP at
Report Object to the AAVSO as: U SCO
Congratulations to Barbara Harris for her discovery!
Clear skies,
Matthew Templeton, AAVSO
Bradley Schaefer, LSU

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