Dear colleagues,
I have just finished analysing my unfiltered CCD observations of
ASASSN-22ho, obtained on 2022, June 02/03 at CBA Belgium Observatory, using
a 0.40-m f/10.0 telescope and QHY-286M CMOS camera under clear skies.
Regular superhumps with an amplitude of 0.35 mag are very clearly visible in
the resulting light curve, establishing ASASSN-22ho as a new SU UMa-type
dwarf nova. A period analysis using the ANOVA, Lomb-Scargle,
Generalized-Lomb-Scargle and PDM methods (Peranso 3.0), yields a combined
(long) superhump period of 0.0902 +/- 0.0025d. The object was at mag CV =
16.5 on Jun 03rd.
I will send my observations to AAVSO, CBA and VSNET for further analysis.
Best regards
Tonny
---
Tonny Vanmunster
CBA Belgium Observatory
CBA Extremadura Observatory
http://www.cbabelgium.com
PERANSO : The Light Curve and Period Analysis Software
http://www.peranso.com
Re: ASASSN-18su
Superhumps were already detected during the 2018 superoutburst
by Berto Monard. Superhumps appeared on 2018 Aug. 25.
Due to the short visibility, the period was not determined.
ASASSN-18su (UG)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=623474
ASASSN-18su was discovered on 2018 August 17.
Unfortunately that outburst could be followed for only few days.
After the seasonal gap a very long fading tail can be seen in
ATLAS forced photometry data.
T. Kato wrote (vsnet-alert 22429):
"The Gaia proper motion is comparable to that of OV Boo ...
ASASSN-18su looks likely a population II CV candidate."
The current outburst was detected by Rod Stubbings at mv= 11.3
on 2022 June 28.537 UT (vsnet-outburst 28822, vsnet-alert 26852).
It had already started on June 24 and is 1.5 magnitudes fainter
than the 2018 outburst according to ASAS-SN Sky Patrol data:
https://asas-sn.osu.edu/sky-patrol/coordinate/52d16cd1-3548-431f-a7fc-326e3…
Time-resolved photometry is urgently required.
Clear skies,
Patrick
-------
References:
All-Sky Automated Survey for Supernovae (ASAS-SN) Sky Patrol:
- Shappee et al., 2014ApJ...788...48S
- Kochanek et al., 2017PASP..129j4502K
Asteroid Terrestrial-impact Last Alert System (ATLAS):
- Tonry et al., 2018PASP..130f4505T
ASASSN-18su is in outburst. Last known outburst was in 2018.
ASASSN-18su 220628.537 113
--
Rod Stubbings
Tetoora Road Observatory
Victoria, Australia
Telescope: "Infinity" 22" f/3.8
stubbo(a)dcsi.net.au
http://rodstubbingsobservatory.wordpress.com/
TCP J15244460-6059200 (N)
(submitted to VSX)
RA 15h24m47.62s DE -60°59'47.3" (Gaia DR3, equinox and epoch J2000.0)
Discoverer: Andrew Pearce (Nedlands, Western Australia)
http://www.cbat.eps.harvard.edu/unconf/followups/J15244460-6059200.html
Elias Aydi et al.: "SOAR spectroscopic follow-up of the Galactic optical
transient TCP J15244460-6059200" (ATel #15473):
https://www.astronomerstelegram.org/?read=15473
Quote:
"The spectrum resembles that of a very fast classical nova after optical peak.
The low amplitude of the transient raises questions about its nature and the
possible progenitor match. TCP J15244460-6059200 could be an unusually
low-amplitude, ultra-fast nova or a more exotic phenomenon. There is a
slight chance that the actual progenitor system is much fainter and coincides
with the bright (~14 mag) match, which would explain the unusually low-
amplitude of the transient."
The likely progenitor is the Gaia DR3 source 5875610751015084544
(Gmag. 13.75, BP-RP= 0.73, Teff ~22500 K, parallax 0.11 ± 0.02 mas,
distance 6.5 ± 0.8 kpc).
SMSS data: gPSF= 13.98, rPSF= 13.70, iPSF= 13.74
APASS data: V= 13.88, B= 14.35, g'= 14.08, r'= 13.70, i'= 13.65
So the eruption amplitude seems to be only 3 magnitudes!
And the likely progenitor does not look like a typical CV in quiescence.
ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and
Kochanek et al. 2017PASP..129j4502K) light curves and data:
https://asas-sn.osu.edu/sky-patrol/coordinate/63cd3b67-9d82-41da-869e-4d122…https://asas-sn.osu.edu/sky-patrol/coordinate/a61c2edb-9cab-4d5c-b9cf-f886b…
TCPJ15244460-6059200 20220619.1200 14.00g ASN
TCPJ15244460-6059200 20220625.2002 10.91g ASN
TCPJ15244460-6059200 20220625.2015 10.92g ASN
TCPJ15244460-6059200 20220625.2027 10.97g ASN
TCPJ15244460-6059200 20220625.9486 12.00g ASN
TCPJ15244460-6059200 20220625.9498 11.96g ASN
TCPJ15244460-6059200 20220625.9510 12.00g ASN
TCPJ15244460-6059200 20220626.2656 12.28g ASN
TCPJ15244460-6059200 20220626.2668 12.27g ASN
TCPJ15244460-6059200 20220626.2682 12.28g ASN
TCPJ15244460-6059200 20220626.9602 12.71g ASN
TCPJ15244460-6059200 20220626.9615 12.65g ASN
TCPJ15244460-6059200 20220626.9628 12.81g ASN
Could the apparent fading trend in ASAS-3 data be real?
http://www.astrouw.edu.pl/cgi-asas/asas_variable/152448-6059.8,asas3,0,9755…
Further spectroscopy and multiband photometry are required.
Clear skies,
Patrick
TCP J22561804+4109534 (UG:)
(submitted to VSX)
RA 22h56m18.05s +41°09'54.3" (J2000.0, Pan-STARRS1)
2022 June 26.6897 UT, mag. 14.0 (CMOS camera, unfiltered)
Discoverer: Yuji Nakamura (Kameyama, Mie, Japan)
2022 06 26.6897 UT
Discovered by Yuji Nakamura, Kameyama, Mie, Japan, on two
frames (30-s exp. limiting mag 16.0) taken by 10cm/F3.0
refractor and CMOS camera. Nothing is visible at this location
on the frames taken on 2022 June 18.7097 UT (30-s exp.
limiting mag 16.0) by same instrument. --- Isao Endoh (NAOJ)
http://www.cbat.eps.harvard.edu/unconf/followups/J22561804+4109534.html
Complete ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S
and Kochanek et al. 2017PASP..129j4502K) light curve and data:
https://asas-sn.osu.edu/sky-patrol/coordinate/a342649c-16c0-43e6-86f6-933b9…
TCPJ22561804+4109534 20220624.4688 <17.55g ASN
TCPJ22561804+4109534 20220626.3301 14.70g ASN
TCPJ22561804+4109534 20220626.3314 14.76g ASN
TCPJ22561804+4109534 20220626.3326 14.74g ASN
TCPJ22561804+4109534 20220626.3379 14.71g ASN
TCPJ22561804+4109534 20220626.3391 14.72g ASN
TCPJ22561804+4109534 20220626.3404 14.69g ASN
Time-resolved and multiband (V, B, ...) photometry are required
(spectroscopy is also encouraged).
Clear skies,
Patrick
Observer: Filipp Romanov (Russia).
Remotely using T30 (iTelescope.Net): 0.50-m f/6.8 reflector of Siding
Spring Observatory (Australia):
TCPJ15244460-6059200 20220625.6794 11.25V RFD 0.01
TCPJ15244460-6059200 20220625.6822 12.03B RFD 0.03
TCPJ15244460-6059200 20220625.6849 10.37R RFD 0.01
The object's position is almost the same as the source
5875610751015084544 in the Gaia DR3 catalogue. The ASAS-SN light
curve: https://asas-sn.osu.edu/sky-patrol/coordinate/5adadbd1-c25e-4aab-9060-fa7ce…
(indicates that the object did not change brightness significantly
before 2022-06-25.200 when it had g mag = 10.9).