CVnet - Cataclysmic Variables Network

AAVSO Alert Notice 714: 

TCP J21040470+4631129 to be observed with HST
August 6, 2020

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Campaigns and Observation Reports:
- Cataclysmic Variables:
Please subscribe to these threads if you are participating in the campaign so you can be updated by the astronomers and by HQ. Join in the discussion or ask questions there!

(Note: This campaign was originally scheduled for March and April but was postponed due to the outburst of the system in March 2020.)

Dr. Boris Gaensicke (University of Warwick) has requested AAVSO assistance in monitoring the WZ Sge-type dwarf nova TCP J21040470+4631129 (Cygnus) in support of observations scheduled with the Hubble Space Telecope for sometime between 2020 September 8 and 20.

All dates in this Alert Notice will be refined when the exact date/time of the HST observations is released by STScI. It is extremely important for observers to subscribe to the forum threads given above for the campaign so as to be informed of the exact date and time of the HST observations. This Alert Notice will also be updated with the exact date and time.

AAVSO observations are essential to know the state of TCP J21040470+4631129 in order to ensure that the system is NOT in outburst when observed with HST. AAVSO observations made 24 hours before the HST observing time will be used to make a go/no-go decision; AAVSO data will be used in the analysis of the resulting HST data.

Nightly snapshots in V are requested beginning now and continuing through September 25 (date may change). Intensive monitoring is requested September 6 - 20 (dates will change). During the period of intensive observations, prompt submission of observations will be essential. The most critical need for a positive observation is the night that is 24 hours before the HST observations (to be announced). Visual observations are also welcome.

TCP J21040470+4631129 has a range in V of 8.4-18.1. Its last major outburst occurred in July 2019, when it reached magnitude 8.293 V, and was followed by several re-brightenings, the most recent of which occurred in March 2020. The most recent observation of TCP J21040470+4631129 in the AAVSO International Database shows it at magnitude 15.248 V +/-0.083 on 2020 Aug. 05.0108 UT (S. Dufoer, Brussels, Belgium).

Coordinates (J2000): R.A. 21 04 04.68  Dec. +46 31 14.5

Charts with comparison stars for TCP J21040470+4631129 may be created using the AAVSO Variable Star Plotter (VSP).

Please report all observations to the AAVSO International Database using the name TCP J21040470+4631129.

This Alert Notice was compiled by Elizabeth O. Waagen.

AAVSO Alert Notice 713: Unusual Nova in Aquila:
Nova Aquilae 2020 No. 2 
= PGIR20eig = AT 2020qpq 

Note: The table of Observations submitted to the AAVSO was replaced to correct errors in this table in the original version of the Alert Notice.  -  Elizabeth O. Waagen, 3 August 2020

3 August 2020

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Time Sensitive Alerts:
- Novae:

Please subscribe to these threads if you are observing this nova so you can be updated as to its behavior and any observing campaigns on it. Join in the discussion or ask questions there!

Event: Unusual Nova in Aquila: N Aql 2020 No. 2 = AT 2020qpq = PGIR20eig

Discovered by: Palomar Gattini-IR collaboration (PGIR)

Discovery magnitude: 13.35 J +- 0.22
Discovery date: 2020 July 13.26 UT

Coordinates (2000.0): R.A. 19 14 26.27   Decl. +14 44 40.1   (from VSX page for N Aql 2020 No. 2)

Spectra: A spectrum obtained by De et al. (ATel #13914) on 2020 August 2 UT using the SED Machine spectrograph on the Palomar 60-inch telescope shows the object to be a reddened classical nova.

Observing recommendations: This nova is unusual in that it has been brightening for 20+ days. It is faint but it may keep brightening for some time as a Type B or C nova (or something else) so starting coverage now could be really valuable. Please observe the nova as it evolves, with observations of all types (visual, CCD, DSLR, spectroscopy) and multiple bands as instrumentation permits.

Observations reported to the AAVSO:

Observations reported to the AAVSO (corrected from initial version):
2020 Jul. 11 UT, <13.7 J (Palomar-Gattini, via ATel #13914);
13.26, 13.35 J (Palomar-Gattini, discovery observation, via ATel #13914);
14.3359 17.488 g +/-0.098 (Zwicky Transient Factory (ZTF), from Lasair website);
18.3937 16.259 r +/-0.035 (ZTF);
21.3633 16.263 r +/-0.048 (ZTF);
24.3378 15.869 r +/-0.035 (ZTF);
26.3545 15.783 r +/-0.047 (ZTF);
27.2528 17.323 g +/-0.038 (ZTF);
27.3172 15.659 r +/-0.040 (ZTF);
31, 12.55 J +/- 0.11 (Palomar-Gattini), via ATel #13914);
31.2900 15.431 r +/-0.037 (ZTF);
31.2904 15.472 r +/-0.045 (ZTF);
Aug. 02.2509 16.976 g +/-0.041 (ZTF);
02.2746 15.172 r +/-0.027 (ZTF);

Corrected ZTF magnitudes are courtesy of S. Otero (AAVSO HQ), who also notes that the ZTF g and r magnitudes from August 2 may be used to derive a V magnitude = 15.9.

Charts: Charts with comparison stars for N Aql 2020 No. 2 may be created using the AAVSO Variable Star Plotter (VSP). Be sure to include spaces in the name as shown. There are magnitude ~12 and ~13 stars nearby to the East, so please be careful in identifying the nova, especially as it fades.

Submit observations: Please submit observations using the name N AQL 2020 NO. 2.
When a GCVS name is assigned to this nova, please use it when submitting observations.
 - Submit optical observations to the AAVSO International Database using WebObs (see below).
 - Submit spectra to the AAVSO Spectroscopy Database (AVSpec).

a. Discovery announced by De et al. in ATel #13914 (2020).

b. De at al. report no source was found at their location on archival 2MASS images.

c. Position end figures
- De et al. (2020 Jul. 13 UT): 26.3s, 40.0"

Congratulations to the Palomar Gattini-IR collaboration on this discovery!

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.


Last updated 07:30 on 10 August 2020

(All objects mentioned in this section are in the International Variable Star Index; additionally, VSX links have been given for selected cataclysmic variables) 

New outbursts and unusual activity reported in the last 72 hours


V2276 Sgr

AR And
FO Aql
AY Lyr
CY Lyr
ASASSN-14cv # (20200808; UGWZ, third rebrightening)

Current superoutbursts (since ...)
ASASSN-17dg (20200713)
ASASSN-14cv # (20200710; UGWZ, rebrightenings on 20200729, 20200802, and 20200808)
KK Tel (20200625, UGSU)
ASASSN-16it (20200622, UGSU)
TY Vul (20200621, UGSU)
ASASSN-13bm (20200620, UGSU)
UV Per (20200620, UGSU; rebrightening on 20200710)
BC Dor (20200619, UGSU)
TCP J02041514+4053325 # (20200616; UGWZ:, time-resolved photometry is required)
PQ And # (20200528; UGWZ:, first recorded outburst since discovery in 1988)
Gaia20cfj (20200509)
SDSS J124058.03-015919.2 # (20200429; AM CVn star, 7 rebrightenings, Psh= 0.02598(5) d) 

Z Cam-type dwarf novae at standstill
HL CMa (since 20191106 or earlier)
Z Cam (since 20181012)
V2837 Ori (20191106–20191123; IW And star, eclipsing, Porb= 0.2761069 d)
CK Eri (20190925–20191029, outburst 20191030; IW And star?)
RX And (20190614–20190714)
V507 Cyg (20190403–20190706, IW And star)
AT Cnc (20190212 – 20190603)
1RXS J062954.6-033520 (20190228–20190316)
UY Pup (20181129–20181217)

# 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.


29 July 2020

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