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AAVSO Alert Notice 623

Observations of V1017 Sagittarii (Nova Sgr 1919) requested

16 March 2018

Dr. Jennifer Sokoloski (Columbia University) and colleagues (led by Dr. Koji Mukai, NASA Goddard Space Flight Center) have requested AAVSO assistance in observing the nova/dwarf nova V1017 Sgr in preparation for an XMM-Newton observation scheduled for 2018 March 23 or 24.

Confirmation that the system is not in dwarf-nova outburst as of March 23 is needed so that the XMM observation may take place.

Observers are requested to obtain a few observations in V or CV between now and March 23 "to tell us whether it is at about 13th or 14th mag or significantly brighter." It is essential to have a positive measurement on March 22. Visual observations are welcome.

Coordinates (2000.0):  R.A. 18 32 04.47   Dec. -29 23 12.6

Charts with a comparison star sequence for V1017 Sgr may be plotted using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the name V1017 SGR.

This observing campaign is being followed on the AAVSO Campaigns and Observing Reports online forum at

This AAVSO Alert Notice was compiled by Elizabeth O. Waagen

AAVSO Alert Notice 622

Nova Ophiuchi 2018 No. 2 = TCP J17140253-2849233 = PNV J17140261-2849237

15 March 2018

Event: Nova in Ophiuchus – N Oph 2018 No. 2 = PNV J17140261-2849237 = PNV J17140261-2849237

Discovered independently by:
- Hideo Nishimura (Kakegawa, Shizuoka-ken, Japan, reported by S. Nakano)
- Tadashi Kojima (Tsumagoi, Gunma-ken, Japan, reported by S. Nakano)
- Koichi Nishiyama (Kurume, Japan) and Fujio Kabashima (Miyaki, Japan)

Discovery magnitude:
- Nishimura: unfiltered CCD magnitude 9.5 (using a Canon EOS 6D digital camera + 200-mm f/3.2 lens)
- Kojima: unfiltered CCD magnitude 9.5 (using a Canon EOS 6D digital camera + 200-mm f/3.2 lens)
- Nishiyama and Kabashima: unfiltered CCD magnitude 9.5 (using a 120-mm f/4 camera lens + FLI09000 camera)

Discovery date:
- Nishimura:  2018 March 10.805 UT
- Kojima: 2018 March 10.807 UT
- Nishiyama and Kabashima: 2018 March 10.814 UT

Coordinates (2000.0): R.A. 17 14 02.53  Decl. -28 49 23.3  (from VSX)
Spectra: Low-resolution spectroscopy indicating that PNV J16484962-4457032 is a Fe II type nova in the stages was obtained by S. C. Williams et al. (ATel #11398) using the FRODOSpec spectrograph on the 2-m Liverpool Telescope.

Observing recommendations: Observations of all types (visual, CCD, DSLR, spectroscopy) and multiple bands as instrumentation permits are strongly encouraged as the nova evolves. Dr. Koji Mukai (NASA Goddard Space Flight Center) recommends that observers use B, V, and I filters if possible to enable studying any color changes.

Observations reported to the AAVSO:
2018 March 02.836 UT, <14.7 (unfiltered CCD magnitude, Nishimura; via CBET 4492);
03.812, 12.0 (unfiltered CCD magnitude, Kojima; via CBET 4492);
03.815, <13.3 (K. Nishiyama and F. Kabashima; via CBET 4492);
06.3623, <15.5 V (ASAS-SN Sky Patrol observation, reported by P. Schmeer (Saarbruecken-Bischmisheim, Germany);
09.813, 10.9 (K. Nishiyama and F. Kabashima; via CBET 4492);
10.753, 9.5  (unfiltered CCD magnitude, A. Takao, Kitakyusgu, Japan; via CBET 4492);
10.81377, 9.5 (unfiltered CCD magnitude, K. Nishiyama and F. Kabashima);
10.81806 UT, 10.0 (A. Pearce, Nedlands, W. Australia);
11.22847, 9.5 (A. Amorim, Florianapolis, Brazil);
11.29653, 9.4 (Amorim);
11.67600, 10.06 B +/-0.05 (S. O'Connor, St. George, Bermuda);
11.67700, 9.42 V +/-0.07 (O'Connor);
11.67800, 8.45 I +/-0.08 (O'Connor);
11.696, 10.05 B (S. Kiyota, Kamagaya, Japan, 0.43-m f/6.8 CDK astrograph + FLI PL4710 CCD (T17, iTelescope.NET), Siding Spring Observatory, NSW, Australia; via CBET 4492);
11.696, 9.53 V (Kiyota, via CBET 4492);
11.696, 9.32 Rc (Kiyota, via CBET 4492);
11.696, 8.99 Ic (Kiyota, via CBET 4492);
11.74236, 9.635 V +/-0.001 (Pearce);
11.74310, 10.189B +/-0.002 (Pearce);
11.81390, 9.4 (Pearce);
11.827, 10.22 B (K. Yoshimoto, Yamaguchi-ken, Japan, via CBET 4492);
11.827, 9.54 V (Yoshimoto, via CBET 4492);
11.827, 9.09 Rc (Yoshimoto, via CBET 4492);
11.827, 8.66 Ic (Yoshimoto, via CBET 4492);
12.32361, 9.3 (Amorim);
12.79240, 9.5 (Amorim);
13.15486, 9.8 (M. Deconinck, Artignosc sur Verdon, France);
14.16250, 10.0 (Deconinck).

Charts: Charts with a comparison star sequence for N Oph 2018 No. 2 may be created using the AAVSO Variable Star Plotter (VSP).

Submit observations: Please submit observations to the AAVSO International Database using the name N OPH 2018 NO. 2. Once a GCVS name is announced in an IAU Circular or CBET, please use that name.

Forums: N Oph 2018 No. 2 is the topic of the AAVSO Novae forum thread

a. Designated PNV J17140261-2849237 and TCP J17140253-2849233 when posted independently by Nishimura and by Kojima, and by Nishiyama and Kabashima, respectively, to the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP). Unless otherwise noted and except for observations reported to the AAVSO, the information in this Alert Notice is taken from IAU CBET 4492.

b. Nishiyama and Kabashima confirmed their discovery immediately on unfiltered CCD frames taken around 2018 Mar 10.830 UT.

c. Nishiyama and Kabashima report nothing was seen on DSS or USNO-B1.0 images.

d. Nishiyama and Kabashima report the nearest star in USNO B1.0 has position end figures 02s787, 26"76, distance 4"8, magnitudes B2=17.35, R2=17.17, I=14.90.

e. Position end figures (J2000.0)
- Nishimura (2018 March 10.805 UT, discovery): 02.61s, 23.7"
- Nishiyama and Kabashima (2018 March 10.830 UT): 02.53s, 23.3"
- T. Kojima (2018 Mar. 10.807 UT, discovery): 02.50s, 23.5"
- K. Yoshimoto (2018 Mar.11.827): 02.55s, 23.7"

f. Images
- H. Nishimura (2018 Mar. 10.805 UT):
- S. Kiyota (2018 March 11.6965 UT):
- K. Yoshimoto (2018 Mar. 11.827 UT):

Congratulations to Hideo Nishimura, to Tadashi Kojima, and to Koichi Nishiyama and Fujio Kabashima on their latest discoveries!

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

AAVSO Alert Notice 620

Coverage of Nova LMC 1996 (OGLE-2018-NOVA-01) eruption needed now

14 March 2018

Dr. Frederick Walter (Stoney Brook University) has requested AAVSO observers, particularly those in South Africa, Australia, and New Zealand, to monitor the current eruption of the recurrent nova Nova LMC 1996 = OGLE-2018-NOVA-01.

The progenitor of this nova has eclipses every 2.85 days. Observations of the current eruption indicate that the eclipse appears to be out of phase. To confirm this, optical photometry is needed urgently, beginning immediately.

Dr. Walter writes: "Nightly observations for the [next] month or two [through 2018 May 15] would be most useful, since it's only up for a few hours at the start of the night. V is fine – in fact, a long time series in one band is preferable to a mixture. However, if [an observer] has the filters, a BVRI sequence each night would be better than B alone (I'm getting BVRIJHK from Chile). And if possible, sitting on it for a couple of hours when it is eclipsing would be useful. But we do not know the ephemeris well yet – just the period (2.85 days)."

The Large Magellanic Cloud is not very well placed at present for observations from Chile, so observers in South Africa, Australia, and New Zealand are urged to observe the nova as it declines. The current eruption is only the second one detected in Nova LMC 1996 (P. Mroz and A. Udalski on behalf of the OGLE team, (ATel #11384). Spectroscopy by Walter shows the nova is an optically thin He-N nova (ATel #11390).

L. Chomiuk et al. (ATel #11392) report that ASAS-SN monitoring of the LMC shows the present eruption was undetected down to <16.3 V before 2018 February 25. On 2018 February 25.16 UT, it was in eruption at V = 11.0 mag.

Dr. Walter reports that on March 11 Nova LMC 1996 was magnitude ~14.7 V, and on March 12 it was magnitude 16.4 V (in eclipse?), and is fading.

Coordinates (2000.0):  R.A. 05 13 32.71   Dec. -68 38 00.4

Charts with a comparison star sequence for Nova LMC 1996 may be plotted using the AAVSO Variable Star Plotter (VSP). A finder chart showing the nova (but without comparison stars) prepared by Dr. Walter is available at:

Please submit observations to the AAVSO International Database using the name NOVA LMC 1996.

This observing campaign is being followed on the AAVSO Campaigns and Observing Reports online forum at:

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


AAVSO Alert Notice 618

Monitoring SDSS J153817.35+512338.0 for HST observations

5 March 2018

Anna Pala (Ph.D. candidate, University of Warwick) has requested AAVSO observers' assistance in monitoring the faint polar cataclysmic variable SDSS J153817.35+512338.0 in support of Hubble Space Telescope observations scheduled for late March – early April 2018.

The HST observing window is 2018 March 28 – April 9. Once the exact time of the HST observations is known, it will be announced on the AAVSO discussion forum thread for this campaign given below.

Pala writes: "... SDSS J153817.35+512338.0 [is] a short period CV (Porb = 93.11 min) that hosts an unexpectedly hot white dwarf (T ~ 30000 K). This high temperature could be a clue of a nova eruption within the past few thousand years and the HST observations will help us in identifying possible ashes and the expanding circumstellar gas shell expected in this case."

It is essential to know the brightness of the target just prior to the HST observations in order to protect the satellite equipment. A go/nogo decision will be made 24 hours prior to the observation time based on positive magnitude reports from AAVSO observers.

Beginning immediately, nightly V/CV (unfiltered) observations are requested. From March 28 through April 9, multiple observations per night (not time series) in V/CV are requested, then nightly observations again through April 30.

J153817.35+512338.0 has a range of 17.5 – 19.1 CV. In its current low (quiescent) state it is magnitude ~18.6 V.

Coordinates (2000.0):  R.A. 15 38 17.34   Dec.  +51 23 38.0

Charts with a comparison star sequence for SDSS J153817.35+512338.0 may be plotted using the AAVSO Variable Star Plotter (VSP). Be sure to include the space between SDSS and J. It is recommended to select the option to display a DSS chart so that all of the comp star images will show.

Please submit observations to the AAVSO International Database using the name SDSS J153817.35+512338.0. Again, please be sure to put a space between SDSS and J.

This observing campaign is being followed on the AAVSO Campaigns and Observing Reports online forum at

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

AAVSO Alert Notice 617

Multiwavelength observations of YZ Cnc, SU UMa, and CR Boo outbursts

5 March 2018

Bob Jacobs (Ph.D. candidate, Radboud University) and Drs. Samaya Nissanke (Radboud University), Jennifer Barnes (Columbia University), and Deanne Coppejans (Northwestern University) have requested AAVSO observers' assistance in monitoring the cataclysmic variables YZ Cnc, SU UMa, and CR Boo. The goal is to build good multicolor light curves of two outbursts of CR Boo and two superoutbursts each of YZ Cnc and SU UMa.

Nightly observations of these stars in any Johnson-Cousins band are requested. When an appropriate outburst occurs, observers should switch to multiple observations per night in 3 or more (more preferred) Johnson-Cousins bands (U, B, V, R, I, J, H, K) spread across the spectrum if possible. It is essential to switch to the higher cadence and multiple bands as soon as possible after the outburst begins. Continue until the star returns to minimum, then resume nightly observations. Visual observations are welcome and are encouraged.

The astronomers want to catch the target outbursts as early as possible. If you see an outburst beginning, please notify the AAVSO immediately via the forum thread for this campaign, and submit your observation(s) as soon as possible.

The astronomers provide the following background information: "Last year's Nobel Prize in Physics went to three researchers in the field of gravitational waves. Two weeks later gravitational wave astronomers announced the discovery of a gravitational wave signal from a merger of two neutron stars. This system also emitted optical light right after the merger and it was observed by many telescopes on the southern hemisphere. The new type of transient was called a "kilonova" or "macronova". When two neutron stars merge, they emit large amounts of matter in ejecta (on the order of 1/100th-1/10th the mass of the Sun). These ejecta are neutron rich. Atoms in the ejecta will capture these neutrons and become much heavier than the atoms created in supernovae. They subsequently decay to stable elements like gold and platinum, heating up the ejecta and making it emit optical and infrared light. Kilonovae could account for all of the gold and platinum in the universe. That's why we would like to observe more kilonovae and test this hypothesis (plus many more). Kilonova observations will also put tighter constraints on gravitational waveforms and therefore the theory of General Relativity. Because kilonovae last for only ~10 days, it's important to catch them as early as possible, which requires good observing strategies.

"In order to observe more kilonovae the Radboud University, KU Leuven and NOVA are building the optical telescope BlackGEM in Chile. Upon an alert from the gravitational wave observatories, BlackGEM, together with other observatories, will try to discover the kilonova as quickly as possible. In order to find optimal observing strategies to find the kilonova as quickly as possible, we are trying to simulate how many transients of each type (e.g. Supernovae, dwarf novae, AM CVNs etc.) one would see in what parts of the sky with BlackGEM in each of its color-bands. These transients could be false-positives in the search for the kilonova: they may be indistinguishable from kilonovae. We want to have as few false-positives and as many correctly identified kilonovae as possible. The simulator will also be applicable in other fields of astronomy where estimates are needed for the variability of the night sky.

"For our simulation we use photometry from telescopes to model the temporal evolution of transients. Thanks to the AAVSO community we already have excellent multi-color light curves for SS Cyg and Z Cam type cataclysmic variable outbursts (U Gem and RX And). Unfortunately there aren't yet any light curves available for SU UMa or AM CVn type outbursts with sufficient multi-color coverage to use in our models.

"With your help we look forward to seeing the first well-sampled multi-color observations of CR Boo, SU UMa, and YZ Cnc in outburst."


Name R.A. (2000.0) Dec (2000.0)
YZ Cnc 08 10 56.65 +28 08 33.2
SU UMa 08 12 28.28 +62 36 22.3
CR Boo 13 48 55.22 +07 57 35.7

Charts with comparison star sequences for YZ Cnc, SU UMa, and CR Boo may be plotted using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the names YZ CNC, SU UMA, and CR BOO.

This observing campaign is being followed on the AAVSO Campaigns and Observing Reports online forum at

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 17:47 UT on 17 March 2018

New outbursts and unusual activity reported in the last 72 hours


ASASSN-18fl (07 45 39.19 -10 08 59.9, V= 13.9 mag)

V792 Cyg
V811 Cyg
CY Lyr
V3941 Sgr
IY UMa (UGSU, eclipsing)
ASASSN-18fk (12 08 57.24 +19 16 56.7, g= 12.5 mag)
DDE 20
MASTER OT J062323.48+730744.0 
MASTER OT J174816.22+501723.3

V359 Cen
TW Vir
ASASSN-14dw (superoutburst?)

OQ Car
V485 Cen
KY Eri
LT Eri
UV Gem
WX Hyi

Current superoutbursts (since ...)
SDSS J162520.29+120308.7 (20180309)
TU Men (20180306)
CI UMa (20180306)
ASASSN-18eu (20180306; superhump period 0.057874 d)
OGLE-BLG-DN-0254 (20180305; eclipsing, Porb= 0.07193083 d)
ASASSN-18ep (20180303; Psh= 
0.0564 d)
MASTER OT J072948.66+593824.4 (20180301)
BR Lup (20180226)
CRTS J063644.9-182531 # (20180223)
ASASSN-18do # (20180221; UGWZ, eclipsing, Psh= 0.054982 d)
ASASSN-13bc (20180219)
NY Ser # (20180120:, long-lasting bright state = standstill)

Z Cam-type dwarf novae at standstill
AT Cnc (since 20180202)
NY Ser # (since about 20180120, UGSU)
TZ Per (since 20171226)
HL CMa (since 20171221) 
IW And (since about 20171219)
Z Cam (20170405–20171207, 246 days)
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.


Updated March 9 2018

For new papers on CV's see astro-ph

Mariko Kimura, Keisuke Isogai, Taichi Kato, Kenta Taguchi, Yasuyuki Wakamatsu, Franz-Josef Hambsch, Berto Monard, Gordon Myers, Shawn Dvorak, Peter Starr, Stephen M. Brincat, Enrique de Miguel, Joseph Ulowetz, Hiroshi Itoh, Geoff Stone, Daisaku Nogami

Joseph Patterson et al.

Paula Szkody, Mark E. Everett, Zhibin Dai, Donald Serna-Grey

John R. Thorstensen, Frederick A. Ringwald, Cynthia J. Taylor, Holly A. Sheets, Christopher S. Peters, Julie N. Skinner, Erek H. Alper, Kathryn E. Weil

Mariko Kato (Keio Univ.), Izumi Hachisu (Univ. of Tokyo), Hideyuki Saio (Tohoku Univ.)

E. Aydi, K. L. Page, N. P. M. Kuin, M. J. Darnley, F. M. Walter, P. Mróz, D. Buckley, S. Mohamed, P. Whitelock, P. Woudt, S. C. Williams, M. Orio, R. E. Williams, A. P. Beardmore, J. P. Osborne, A. Kniazev, V. A. R. M. Ribeiro, A. Udalski, J. Strader, L. Chomiuk

Michael M. Shara, Trisha F. Doyle, Ashley Pagnotta, James T. Garland, Tod R. Lauer, David Zurek, Edward A. Baltz, Ariel Goerl, Attay Kovetz, Tamara Machac, Juan Madrid, Joanna Mikolajewska, J. D. Neill, Dina Prialnik, Doug L. Welch, Ofer Yaron

J.M Hameury & J.P Lasota

V. V. Lukin, K. L. Malanchev, N. I. Shakura, K. A. Postnov, V. M. Chechetkin, V. P. Utrobin

Authors: A. F. Pala, B. T. Gänsicke, D. Townsley, D. Boyd, M. J. Cook, D. De Martino, P. Godon, J. B. Haislip, A. A. Henden, I. Hubeny, K. M. Ivarsen, S. Kafka, C. Knigge, A. P. LaCluyze, K. S. Long, T. R. Marsh, B. Monard, J. P. Moore, G. Myers, P. Nelson, D. Nogami, R. Pickard, G. Poyner, D. E. Reichart, D. Rodriguez Perez, M. R. Schreiber, J. Shears, E. M. Sion, R. Stubbings, P. Szkody, M. Zorotovic

Liam K Hardy, Martin J McAllister, Vik S Dhillon, Stuart P Littlefair, Madelon C P Bours, Elme Breedt, Tim Butterley, Anurak Chakpor, Puji Irawati, Paul Kerry, Tom R Marsh, Steven G Parsons, Chris D J Savoury, Richard W Wilson, Patrick A Woudt