@article{22303,
  abstract     = {We present the discovery of AT 2024wpp (‘Whippet’), a fast and luminous 18cow-like transient. At a redshift of z = 0 . 0868 , revealed by Keck Cosmic Web Imager spectroscopy of its faint star-forming host, it is the fourth-nearest example of its class to date. Rapid identification of the source in the Zwicky Transient Facility data stream permitted ultraviolet-through- optical observations to be obtained prior to peak, allowing the first determination of the peak bolometric luminosity ( 2 ×1045 erg s−1 ), maximum photospheric radius ( 1015 cm), and total radiated energy ( 1051 erg) of an 18cow-like object. We present results from a comprehensive multiwavelength observing campaign, including a far-ultraviolet spectrum from the Cosmic Origins Spectrograph on the Hubble Space Telescope and deep imaging extending > 100 d post-explosion from the Very Large Telescope, Hubble Space Telescope , Very Large Array, and Atacama Large Millimetre Array. We interpret the observations under a model in which a rapidly accreting central engine blows a fast ( ∼0.2 c ) wind into the surrounding medium and irradiates it with X-rays. The high Doppler velocities and intense ionization within this wind prevent identifiable spectroscopic features from appearing in the ejecta or in the surrounding circumstellar material. Weak H and He signatures do emerge in the spectra after 35 d in the form of double-peaked narrow lines. Each peak is individually narrow (full width δv ∼3000 km s−1 ) but the two components are separated by v ∼6600 km s−1 , indicating stable structures of denser material, possibly representing streams of tidal ejecta or an ablated companion star.},
  author       = {Perley, Daniel A and Ho, Anna Y Q and McGrath, Zoë and Camilo, Michael and Sevilla, Cassie and Chen, Ping and Schroeder, Genevieve and Govreen-Segal, Taya and Bochenek, Aleksandra and Qin, Yu-Jing and Gillanders, James H and Amend, Benjamin and Anderson, Joseph P and Andreoni, Igor and Aryan, Amar and Bellm, Eric C and Bloom, Joshua S and de Boer, Thomas and Carney, Jonathan and Caiazzo, Ilaria and Chambers, Ken C and Charalampopoulos, Panos and Chen, Ting-Wan and Chen, Tracy X and Coughlin, Eric R and Coughlin, Michael and Dennefeld, Michel and Dimitriadis, Georgios and Fremling, Christoffer and Frostig, Danielle and Gal-Yam, Avishay and Galbany, Lluís and Gangopadhyay, Anjashay and Ghendrih, Melzie and Graham, Matthew J and Gromadzki, Mariusz and Groom, Steven L and Gutiérrez, Claudia P and Hinds, K -Ryan and Huber, Mark E and Inserra, Cosimo and Kaiser, Benjamin C and Kasliwal, Mansi M and Koivisto, Niilo E and Lin, Chien-Cheng and Liu, Chang and Lowe, Thomas B and Magnier, Eugene and Mahabal, Ashish A and Milligan, Andrew and Minguez, Paloma and Mo, Geoffrey and Müller-Bravo, Tomás E and Nicholl, Matt and Pessi, Priscila J and Pignata, Giuliano and Purdum, Josiah and Rehemtulla, Nabeel and Rich, R Michael and Sahu, Anwesha and Singh, Avinash and Smartt, Stephen J and Smith, Ian A and Sollerman, Jesper and Srinivasaragavan, Gokul and Srivastav, Shubham and Stein, Robert D and Schulze, Steve and Tweddle, Jack W and Wainscoat, Richard and Wise, Jacob L and Yan, Lin and Young, David R},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {stars: black holes, supernovae: individual: AT2024wpp, radio continuum: transients},
  number       = {1},
  publisher    = {Oxford University Press},
  title        = {{AT 2024wpp: An extremely luminous fast ultraviolet transient powered by accretion onto a black hole}},
  doi          = {10.1093/mnras/stag678},
  volume       = {549},
  year         = {2026},
}