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AAVSO Alert Notice 606
Observing campaign on nova in Vela – ASASSN-17mt

November 17, 2017

Event: Nova in Vela (ASASSN-17mt) and associated observing campaign

Discovered by: ASAS-SN (K. Z. Stanek (Ohio State University) et al.; ATel #10772)

Discovery magnitude: V=11.3, using data from the quadruple 14-cm "Cassius" telescope at CTIO, Chile

Discovery date: 2017 September 24.39 UT

Coordinates (2000.0):
R.A. 08 50 29.62   Decl. -47 45 28.3 (from VSX)

Spectra: Spectroscopy indicating that ASASSN-17mt is a classical nova in the optically thick (Fe-curtain) stage was obtained 2017 September 28.77 UT by P. Luckas (International Centre for Radio Astronomy Research, Univ. of Western Australia; ARAS Group; ATel #10795).

Observing recommendations: Observations of all types (visual, CCD, DSLR, spectroscopy) and multiple bands as instrumentation permits are strongly encouraged as the nova evolves.

K.-L. Li et al. (Michigan State University) report a likely Fermi-LAT detection of ASASSN-17mt (ATel #10977), and have secured weekly observations with Swift for the next ten weeks. Additional multiwavelength observations may also take place. Increased and continuing optical coverage is essential, with V and I bands the highest priority. Visual observations are welcome.

Observations reported to the AAVSO:
2017 Jul. 07.95 UT, <16.9 V (ASAS-SN, ATel #10772);
Sep. 24.39, 11.3 V (ASAS-SN, discovery observation, ATel #10772);
23.40, 11.3: V (ASAS-SN, ATel #10772);
29.30903, <11.1 (PLA, A. Padilla Filho, Rio de Janeiro, Brazil);
Oct. 03.72370, 10.98 B +/-0.04(OCN, S. O'Connor, St. George, Bermuda);
Oct. 03.72530, 9.80 V +/-0.022(O'Connor);
Oct. 03.72660, 9.07 R +/-0.03 (O'Connor);
Oct. 09.77720, 11.20 TB +/-0.04 (O'Connor);
Oct. 09.77850, 9.95 V +/-0.03 (O'Connor);
Oct. 09.77970, 8.81 R +/-0.03 (O'Connor);
Oct. 09.78080, 7.70 I +/-0.05 (O'Connor);
Oct. 11.82710, 10.0 (PEX, A. Pearce, Nedlands, W. Australia);
Oct. 12.76110, 11.15 B +/-0.05 (O'Connor);
Oct. 12.76200, 9.84 V +/-0.05 (O'Connor);
Oct. 12.82500, 10.1 (Pearce);
Oct. 17.72640, 9.12 V +/-0.03 (O'Connor);
Oct. 17.72740, 6.91 I +/-0.02 (O'Connor);
Oct. 19.81880, 10.1 (Pearce);
Oct. 20.83540, 10.0 (Pearce);
Oct. 21.70180, 10.95 B +/-0.04 (O'Connor);
Oct. 21.70260, 9.79 V +/-0.04 (O'Connor);
Oct. 21.70340, 8.15 R +/-0.09 (O'Connor);
Oct. 24.79310, 10.0 (Pearce);
Oct. 29.80350, 10.8 (Pearce);
Nov. 11.80280, 10.1 (Pearce);
Nov. 13.68150, 10.05 V +/-0.01 (O'Connor);
Nov. 13.68190, 8.54 R +/-0.03 (O'Connor);
Nov. 13.79030, 10.1 (Pearce);
Nov. 15.76810, 10.8 (Pearce);

Charts: Finder charts with a comparison star sequence for ASASSN-17mt may be created using the AAVSO Variable Star Plotter (VSP).

Submit observations: Please submit observations to the AAVSO International Database using the name ASASSN-17mt. Once a GCVS name is announced in an IAU Circular or CBET, please use that name.

Notes:
a. Designated ASASSN-17mt in the course of the ASAS-SN survey. Unless otherwise noted and except for observations reported to the AAVSO, the information in this Alert Notice is taken from ATels #10772, #10774, #10785, and #10795, and #10977.

b. Stanek et al. report that there was an ~80-day seasonal gap in the ASAS-SN coverage before the observations given above, so the nova could have peaked already. Nothing is seen down to <16.9 V at the location of the nova in subtracted images taken on UT 2017-07-07.95 and before. They also report that nothing had been detected since ASAS-SN began observing the location in February 2016.

c. Possible progenitor may be 2MASS J08502962-4745283 = WISE J085029.63-474528.0.

d. This nova is being followed on the AAVSO's Time Sensitive Alerts forum (https://www.aavso.org/asassn-17mt-classical-galactic-nova-11-mag-vela) and its Novae forum (https://www.aavso.org/asassn-17mt-nova-vela).

Congratulations to the ASAS-SN team on this discovery!

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.



AAVSO Alert Notice 598
Intermediate polar FO Aqr fading and photometry needed now

September 6, 2017:  Dr. Colin Littlefield (University of Notre Dame) and colleagues have requested AAVSO assistance in monitoring the intermediate polar cataclysmic variable FO Aqr beginning immediately. This campaign is similar to the one on FO Aqr requested by Dr. Littlefield and colleagues in July 2016 (AAVSO Alert Notice 545).

Dr. Littlefield and co-authors Gordon Myers (AAVSO), Richard Sabo (AAVSO), Peter Garnavich (Notre Dame), and Mark Kennedy (University College Cork) recently published ATel #10703, and write therein that: "The intermediate polar FO Aqr, which in 2016 underwent the first low state in its observational history (Littlefield et al. 2016, ApJ, 833, 93), has faded by nearly 0.7 mag since 2017 August 10, implying a decrease in the system's accretion rate."

Good coverage of the current fading event – only the second observed in this system – is extremely important.

In an email Dr. Littlefield writes: "As with the previous campaign, we would like observers to obtain nightly photometric time series of FO Aqr. In order to maximize their usefulness to us, the observations would need to be either V-filtered or unfiltered with a V zeropoint (i.e., unfiltered but using the V magnitude of a comparison star when performing photometry, CV). We would like observers to use a cadence of 60 sec/image or faster, even if this means observing unfiltered, and we would prefer that each time series last at least an hour (preferably a minimum of 2 hrs). Our hope is that the AAVSO could observe FO Aqr 
until either (1) the end of the current faint state or (2) solar conjunction, which for FO Aqr is in January." Visual observations are also welcome.

He continues: "Because last year's fade began during solar conjunction, the drop to minimum went almost entirely unobserved. If this is the start of another deep low state like the 2016 event, it would be the first opportunity to study how FO Aqr's accretion processes change during the drop to minimum. For example, AAVSO observations of the current fade by observers 
Gordon Myers and Richard Sabo have already provided important evidence of a correlation between FO Aqr's overall brightness and the mechanism by which material accretes onto the system's white dwarf.

"We had 16 AAVSO co-authors on our paper about the 2016 low state, and if observations from the new campaign lead to another publication, we would be pleased to offer co-authorship to AAVSO observers who contribute data used in our analysis."

Observations in the AAVSO International Database on 2017 September 2.6251 UT show FO Aqr at CV = 14.607 +/-0.010 (MGW, G. Myers, Hillsborough, CA). AAVSO data show that during the 2016 fading episode it was as faint as CV = 15.6. FO Aqr's brightness in its high state is V~13.4.

Coordinates (2000.0):
R.A. 22 17 55.38  Dec. -08 21 03.8

Charts: Charts for FO Aqr with an expanded comparison star sequence may be created using the AAVSO Variable Star Plotter (VSP). For observers who have been following FO Aqr as part of the CBA program, the comparison stars used for that program have been retained.

Please submit observations to the AAVSO International Database using the name FO AQR.

This observing campaign is being followed on the AAVSO Campaigns and Observing Reports online forum at https://www.aavso.org/fo-aqr-campaign

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.



It’s all about the  standstills, those episodes where the star gets stuck at a mid-point between maximum and minimum. If it doesn’t exhibit standstills it isn’t a Z Cam star.









Data from Catalina Real Time Survey 

Drake et al. 2009, ApJ, 696, 87




Northern CVs brighter than 17th magnitude here.

Southern CV's brighter than 17th magnitude here.



ACTIVITY AT A GLANCE

Last updated 09:46 UT on 23 November 2017

New outbursts and unusual activity reported in the last 72 hours


YYYYMMDD

20171123
V872 Per

20171122
UU Aql
QU Aqr
MN Dra
WX Hyi
NSV 2026
ASASSN-17pn (new discovery)

20171121
DM CMa
V521 Peg
CC Scl


Current superoutbursts (since ...)
PNV J05580574-0011155 (20171120; Psh~ 0.0586 d)
ER UMa (20171119)
FZ Cet (20171118)
VW Hyi (20171117; precursor on 20171112)
ASASSN-17pb (20171113; Psh~ 0.0820 d)
KP Cas (20171111)
RZ LMi (20171111)
ASASSN-17ou (20171110; Psh= 0.05684 d)
V1208 Tau (20171108; superhumps by MZK 171111)
EG Aqr (20171103)
ASASSN-17of (20171103; Psh~ 0.066 d)
ASASSN-17oo (20171101; Psh= 0.0698 d)
ASASSN-14lk (20171030; Psh= 0.06113 d)
ASASSN-14gq (20171026; precursor on 20171014)
NSV 1440 (20170824; another rebrightening 171104)


Z Cam-type dwarf novae at standstill
Z Cam (since 20170405)
IW And (20170812–20170831, 19 days)
OQ Car (20160415–20170826, 498 days)

# indicates a noteworthy or unusual outburst
:  indicates confirmation required
 
'Activity At A Glance' is gleaned from observations reported to AAVSO MyNewsFlash, BAAVSS-Alert, CVnet-Outburst, VSObs-share and VSNET-outburst. We sincerely thank all the observers who contribute timely observations and reports of activity to these email lists.

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