Okay, found it. Name is:

TCP J20402089+4915562

Re-analysing the images.....

Regrads,

Josch

On 20.05.2025 16:22, Josch Hambsch wrote:

Hi Sebastian,

under which name? ASASSN-25bt is not found by WEBOBS.

Regards,

Josch

On 20.05.2025 16:17, Sebastián Otero wrote:

...

Hi Josch,

it was added to VSX on May 14.

Cheers, Sebastian

...

I have observed this target the past nights. It's not yet in the VSX. Will send the data to you later today. Regards Josch

-----Originele bericht----- Van: Yusuketampo@kusastro.kyoto-u.ac.jp naar: vsnet-outburstvsnet-outburst@ooruri.kusastro.kyoto-u.ac.jp; vsnet-campaign-dnvsnet-campaign-dn@ooruri.kusastro.kyoto-u.ac.jp; vsnet-alertvsnet-alert@ooruri.kusastro.kyoto-u.ac.jp datum: dinsdag 20 mei 2025 10:04 CEST Onderwerp: [vsnet-alert 28062] ZTF18acynctq = TCP J20402089+4915562 = ASASSN-25bt: new SU UMa star candidate

ZTF18acynctq = TCP J20402089+4915562 = ASASSN-25bt: new SU UMa star candidate

XOSS team via TOCP/TNS and ASAS-SN reported the 2025 outburst of this system, which is already known as ZTF18acynctq in its 2018 outburst. https://alerce.online/object/ZTF18acynctq http://www.cbat.eps.harvard.edu/unconf/followups/J20402089+4915562.html https://www.aavso.org/vsx/index.php?view=detail.top&oid=10848612

Its 2018 outburst lasted for ~15 days and showed a possible rebrightening in the ATLAS data. Thus the outburst cycle is ~2300 d. This system is currently ~16.0 mag, and time-resolved observations may detect superhumps.

Best regards, Yusuke

-- Sebastián Otero VSX Team American Association of Variable Star Observers

185 Alewife Brook Pkwy Ste 410 Cambridge, MA  02138-1104 www.aavso.org

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The mission of the AAVSO is to enable anyone, anywhere, to participate in scientific discovery through variable star astronomy.