Alert Notice 821: Bright probable nova in Sco - PNV J17224490-4137160

April 21, 2023

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):

- Time Sensitive Alerts: https://www.aavso.org/probable-nova-in-sco-pnv-j-17224490-4137160
- Novae: https://www.aavso.org/probable-nova-in-sco-pnv-j-17224490-4137160-02
- Spectroscopy: https://www.aavso.org/probable-nova-in-sco-pnv-j-17224490-4137160-01

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

Event: Nova in Scorpius - PNV J17224490-4137160

Discovered by: Andrew Pearce (Nedlands, W. Australia)

Discovery magnitude: 8.0 unfiltered CCD, using Canon 800D digital camera + 85-mm f/1.2 lens

Discovery date: 2023 Apr. 20.6780 UT

Coordinates (2000.0): R.A. 17 22 45.05  Decl. -41 37 16.3  (from VSX page for PNV J17224490-4137160)

Spectra: Spectroscopy indicating the object to be a nova has not been reported as of the publication of this Alert Notice, but given its amplitude (probable precursor V=19.6, derived from Gaia DR3) and location, it is unlikely to be anything other than a galactic nova.

Observing campaign and non-campaign general observing recommendations:

Dr. Kirill Sokolovsky (University of Illinois Urbana-Champaign) has requested AAVSO observers' assistance in obtaining photometry of PNV in support of NuStar X-ray observations scheduled for 2023 Apr 21 21:00 UT - 2023 Apr 23 10:00 UT.

Dr. Sokolovsky writes: "The ideal observation of PNV J17224490-4137160 would be a few hours long time series in V band that overlaps with or is at least close in time to the NuSTAR observing window. All other types of observations including unfiltered time series, individual brightness measurements with photometric filters as well as visual brightness estimates are also useful. (The individual observations will be useful even after the end of the NuSTAR observing window - to trace the overall evolution of this nova.)"

Generally, please observe PNV J17224490-4137160 as it continues to evolve, with observations of all types (visual, CCD/CMOS, DSLR, spectroscopy) and multiple bands as instrumentation permits. Frequency of observation depends on the rate of decline, but Dr. Fred Walter (Stony Brook University) recommends a minimum of one observation per night per band. For spectroscopy, he recommends spectra in blue to observe He II 4686, H-beta, and the Bowen blend (4640A), in addition to H-alpha. Cadence for spectra depends on how fast the nova continues to evolve, but, he adds, "you can't go wrong with a spectrum every clear night."

This object is very bright, and observers are reminded to be careful not to saturate detectors when acquiring images.

Observations reported to the AAVSO:
2023 Apr. 18.69375 UT, <12.5 unfiltered CCD (Andrew Pearce, Nedlands, W. Australia);
19.69028, <12.5 unfiltered CCD (Pearce);
20.6780, 8.0 unfiltered CCD (Pearce);
20.70486, 8.0 (Pearce);
20.70486, 8.0 (Pearce);
20.72153, 7.9 (Pearce);
20.724, 7.60 V (Pearce);
20.724, 8.50 B (Pearce);
20.756, 7.53 V (Pearce);
20.756, 8.51 B (Pearce);
20.75972, 7.6 (Pearce);
20.80069, 9.9 (H. Nishimura, Kakegawa, Shizuoka, Japan, Canon EOS 6D digital camera + 200-mm F/3.0 lens, via TOCP);
20.818, 7.40 V (Pearce);
20.818, 8.35 B (Pearce);
20.855, 7.32 V (Pearce);
20.855, 8.22 B (Pearce);
20.85972, 7.6 (Pearce);
20.88125, 7.5 (Pearce);
21.10417, 7.2(L. Araujo, Pelotas, Brazil);
21.12501, 7.2 (J. De Souza Aguiar, Campinas, Brazil);
21.14306, 7.3 (C. da Silva, Luminarias, Brazil);
21.20139, 7.0 (N. Justino, Sao Vicente, Brazil);
21.25347, 7.0 (A. Padilla Filho, Rio de Janeiro, Brazil);
21.5, 7.8 R (E. Guido, L. Izzo, and A. Valvasori, remotely w/Telescope Live Network, NSW, Australia);
21.66806, 7.4 (Pearce);
21.6809, 7.3 V (Guido, Izzo, and Valvasori);
21.6814, 7.1 R (Guido, Izzo, and Valvasori);
21.72569, 7.4 (Pearce);

Charts: An AAVSO chart with comparison stars for PNV J17224490-4137160 is below. Please use it for now.  This chart may be downloaded here. (We are having some trouble with creating charts for this field via the AAVSO Variable Star Plotter (VSP), but expect to resolve it soon.)

Submit observations: Please submit observations using the name PNV J17224490-4137160. When a GCVS name is assigned, please use it when submitting observations.
 - Submit optical observations to the AAVSO International Database using WebObs.
 - Submit spectra to the AAVSO Spectroscopy Database (AVSpec).
 
Notes:
a. Designated PNV J17224490-4137160 when posted to the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP).

b. S. Otero (AAVSO) and A. Pearce report the likely progenitor is Gaia DR3 5959616875349110656.

c. Images
- E. Guido, L. Izzo, and A. Valvasori (2023 Apr. 21.54 UT, via TOCP):https://tinyurl.com/novascoanimation

d. Position end figures:
- A. Pearce (2023 Apr. 20.724 UT, via TOCP): 45.04s, 16.5"
- E. Guido, L. Izzo, and A. Valvasori (2023 Apr. 21.5 UT): 45.01s, 15.6"

Congratulations to Andrew Pearce on his latest discovery!

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.
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SUBMIT OBSERVATIONS TO THE AAVSO