---
OA_place: publisher
OA_type: hybrid
PlanS_conform: '1'
_id: '21842'
abstract:
- lang: eng
text: "AM CVn stars are ultra-compact semi-detached binaries consisting of a white
dwarf primary and a hydrogen-depleted secondary. In this\r\npaper, we present
spectroscopic and photometric results of 15 transient sources pre-classified as
AM CVn candidates. Our analysis confirms\r\n9 systems of the type AM CVn, 3 hydrogen-rich
cataclysmic variables (accreting white dwarfs with near-main-sequence stars for
donors),\r\nand 3 systems that could be evolved cataclysmic variables. Eight of
the AM CVn stars are analysed spectroscopically for the first time,\r\nwhich increases
the number of spectroscopically confirmed AM CVns by about 10%. TESS data revealed
the orbital period of the AM CVn\r\nstar ASASSN-20pv to be Porb =27.282 min, which
helps to constrain the possible values of its mass ratio. TESS also helped to
determine\r\nthe superhump periods of one AM CVn star (ASASSN-19ct, Psh =30.94
min) and two cataclysmic variables we classify as WZ Sge stars\r\n(Psh =90.77
min for ZTF18aaaasnn and Psh =91.6min for ASASSN-15na).We identified very different
abundances in the spectra of theAM\r\nCVns binaries ASASSN-15kf and ASASSN-20pv
(both Porb ∼27.5min), suggesting different type of donors. Six of the studied
AMCVns are\r\nX-ray sources, which helped to determine their mass accretion rates.
Photometry shows that the duration of all the superoutbursts detected\r\nin the
AM CVns is consistent with expectations from the disc instability model. Finally,
we provide refined criteria for the identification of\r\nnew systems using all-sky
surveys such as LSST."
acknowledgement: "We are grateful to the anonymous referee for providing\r\nus with
useful comments and suggestions that improved our manuscript.\r\nJK and LRS acknowledge
support from NASA grants NNH22ZDA001N-6152\r\nand 80NSSC24K0638. MPM is partially
supported by the Swiss National\r\nScience Foundation IZSTZ0_216537 and by UNAM
PAPIIT-IG101224. Based\r\non observations obtained at the international Gemini Observatory,
a program\r\nof NSF NOIRLab, which is managed by the Association of Universities
for\r\nResearch in Astronomy (AURA) under a cooperative agreement with the U.S.\r\nNational
Science Foundation on behalf of the Gemini Observatory partnership:\r\nthe U.S.
National Science Foundation (United States), National Research\r\nCouncil (Canada),
Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología
e Innovación (Argentina), Ministério\r\nda Ciência, Tecnologia, Inovações e Comunicações
(Brazil), and Korea\r\nAstronomy and Space Science Institute (Republic of Korea).
The Gemini\r\ndata were obtained from programs GN-2023B-Q-310 and GS-2024A-Q-311\r\n(PI:
Rivera Sandoval) and processed using DRAGONS (Data Reduction for\r\nAstronomy from
Gemini Observatory North and South) The Digitized Sky\r\nSurveys were produced at
the Space Telescope Science Institute under U.S.\r\nGovernment grant NAG W-2166.
The images of these surveys are based on\r\nphotographic data obtained using the
Oschin Schmidt Telescope on Palomar\r\nMountain and the UK Schmidt Telescope. The
plates were processed into the\r\npresent compressed digital form with the permission
of these institutions.\r\nThe National Geographic Society – Palomar Observatory
Sky Atlas (POSS-I)\r\nwas made by the California Institute of Technology with grants
from the\r\nNational Geographic Society. The Second Palomar Observatory Sky Survey\r\n(POSS-II)
was made by the California Institute of Technology with funds\r\nfrom the National
Science Foundation, the National Geographic Society, the\r\nSloan Foundation, the
Samuel Oschin Foundation, and the Eastman Kodak\r\nCorporation. The Oschin Schmidt
Telescope is operated by the California\r\nInstitute of Technology and Palomar Observatory.
The UK Schmidt Telescope\r\nwas operated by the Royal Observatory Edinburgh, with
funding from the\r\nUK Science and Engineering Research Council (later the UK Particle
Physics\r\nand Astronomy Research Council), until 1988 June, and thereafter by the\r\nAnglo-Australian
Observatory. The blue plates of the southern Sky Atlas\r\nand its Equatorial Extension
(together known as the SERC-J), as well as the\r\nEquatorial Red (ER), and the Second
Epoch [red] Survey (SES) were all taken\r\nwith the UK Schmidt. Supplemental funding
for sky-survey work at the ST\r\nScI is provided by the European Southern Observatory.
Based on observations\r\nobtained with the Samuel Oschin Telescope 48-inch and the
60-inch Telescope\r\nat the Palomar Observatory as part of the Zwicky Transient
Facility project.\r\nZTF is supported by the National Science Foundation under Grants
No. AST-\r\n1440341 and AST-2034437 and a collaboration including current partners\r\nCaltech,
IPAC, the Oskar Klein Center at Stockholm University, the University\r\nof Maryland,
University of California, Berkeley, the University of Wisconsin\r\nat Milwaukee,
University of Warwick, Ruhr University, Cornell University,\r\nNorthwestern University,
and Drexel University. Operations are conducted\r\nby COO, IPAC, and UW. This work
has used data from the European\r\nSpace Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia),\r\nprocessed
by the Gaia Data Processing and Analysis Consortium (DPAC,\r\nhttps://www.cosmos.esa.int/web/gaia/dpac/consortium).
Funding for the\r\nDPAC has been provided by national institutions, in particular,
the institutions\r\nparticipating in the Gaia Multilateral Agreement. We acknowledge
with\r\nthanks the variable star observations from the AAVSO International Database\r\ncontributed
by observers worldwide and used in this research. This paper\r\nincludes data collected
by the TESS mission. Funding for the TESS mission\r\nis provided by the NASA Science
Mission Directorate. Some of the data\r\npresented in this paper were obtained from
the B. Mikulski Archive for Space\r\nTelescopes (MAST). This research has made use
of the SIMBAD database,\r\noperated at CDS, Strasbourg, France. This research has
made use of ‘Aladin\r\nsky atlas’ developed at CDS, Strasbourg Observatory, France.
This research\r\nhas made use of the VizieR catalogue access tool, CDS, Strasbourg,
France."
article_number: e052
article_processing_charge: Yes (in subscription journal)
article_type: original
author:
- first_name: Jan
full_name: Kára, Jan
last_name: Kára
- first_name: Liliana
full_name: Rivera Sandoval, Liliana
last_name: Rivera Sandoval
- first_name: Wendy
full_name: Mendoza, Wendy
last_name: Mendoza
- first_name: Thomas
full_name: Maccarone, Thomas
last_name: Maccarone
- first_name: Manuel
full_name: Pichardo Marcano, Manuel
last_name: Pichardo Marcano
- first_name: Luis E.
full_name: Salazar Manzano, Luis E.
last_name: Salazar Manzano
- first_name: Ryan J.
full_name: Oelkers, Ryan J.
last_name: Oelkers
- first_name: Joannes C
full_name: van Roestel, Joannes C
id: 4d122fc8-6083-11f0-87a5-97d68b860333
last_name: van Roestel
citation:
ama: Kára J, Rivera Sandoval L, Mendoza W, et al. A study of transients from ground-based
surveys reveals new ultra-compact accreting white dwarf binaries. Publications
of the Astronomical Society of Australia. 2026;43. doi:10.1017/pasa.2026.10184
apa: Kára, J., Rivera Sandoval, L., Mendoza, W., Maccarone, T., Pichardo Marcano,
M., Salazar Manzano, L. E., … van Roestel, J. C. (2026). A study of transients
from ground-based surveys reveals new ultra-compact accreting white dwarf binaries.
Publications of the Astronomical Society of Australia. Cambridge University
Press. https://doi.org/10.1017/pasa.2026.10184
chicago: Kára, Jan, Liliana Rivera Sandoval, Wendy Mendoza, Thomas Maccarone, Manuel
Pichardo Marcano, Luis E. Salazar Manzano, Ryan J. Oelkers, and Joannes C van
Roestel. “A Study of Transients from Ground-Based Surveys Reveals New Ultra-Compact
Accreting White Dwarf Binaries.” Publications of the Astronomical Society of
Australia. Cambridge University Press, 2026. https://doi.org/10.1017/pasa.2026.10184.
ieee: J. Kára et al., “A study of transients from ground-based surveys reveals
new ultra-compact accreting white dwarf binaries,” Publications of the Astronomical
Society of Australia, vol. 43. Cambridge University Press, 2026.
ista: Kára J, Rivera Sandoval L, Mendoza W, Maccarone T, Pichardo Marcano M, Salazar
Manzano LE, Oelkers RJ, van Roestel JC. 2026. A study of transients from ground-based
surveys reveals new ultra-compact accreting white dwarf binaries. Publications
of the Astronomical Society of Australia. 43, e052.
mla: Kára, Jan, et al. “A Study of Transients from Ground-Based Surveys Reveals
New Ultra-Compact Accreting White Dwarf Binaries.” Publications of the Astronomical
Society of Australia, vol. 43, e052, Cambridge University Press, 2026, doi:10.1017/pasa.2026.10184.
short: J. Kára, L. Rivera Sandoval, W. Mendoza, T. Maccarone, M. Pichardo Marcano,
L.E. Salazar Manzano, R.J. Oelkers, J.C. van Roestel, Publications of the Astronomical
Society of Australia 43 (2026).
date_created: 2026-05-07T08:55:00Z
date_published: 2026-03-27T00:00:00Z
date_updated: 2026-05-12T06:57:40Z
day: '27'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1017/pasa.2026.10184
file:
- access_level: open_access
checksum: f8f3cd3765948e8b276176c71c9d4e02
content_type: application/pdf
creator: dernst
date_created: 2026-05-12T06:54:10Z
date_updated: 2026-05-12T06:54:10Z
file_id: '21862'
file_name: 2026_PublAstronomicalSocAustralia_Kara.pdf
file_size: 3681016
relation: main_file
success: 1
file_date_updated: 2026-05-12T06:54:10Z
has_accepted_license: '1'
intvolume: ' 43'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '03'
oa: 1
oa_version: Published Version
publication: Publications of the Astronomical Society of Australia
publication_identifier:
eissn:
- 1448-6083
issn:
- 1323-3580
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: A study of transients from ground-based surveys reveals new ultra-compact accreting
white dwarf binaries
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 43
year: '2026'
...
---
_id: '17541'
abstract:
- lang: eng
text: 'In recent years, the discovery of massive quasars at z~7 has provided a striking
challenge to our understanding of the origin and growth of supermassive black
holes in the early Universe. Mounting observational and theoretical evidence indicates
the viability of massive seeds, formed by the collapse of supermassive stars,
as a progenitor model for such early, massive accreting black holes. Although
considerable progress has been made in our theoretical understanding, many questions
remain regarding how (and how often) such objects may form, how they live and
die, and how next generation observatories may yield new insight into the origin
of these primordial titans. This review focusses on our present understanding
of this remarkable formation scenario, based on discussions held at the Monash
Prato Centre from November 20--24, 2017, during the workshop "Titans of the Early
Universe: The Origin of the First Supermassive Black Holes."'
article_number: e027
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Tyrone E.
full_name: Woods, Tyrone E.
last_name: Woods
- first_name: Bhaskar
full_name: Agarwal, Bhaskar
last_name: Agarwal
- first_name: Volker
full_name: Bromm, Volker
last_name: Bromm
- first_name: Andrew
full_name: Bunker, Andrew
last_name: Bunker
- first_name: Ke-Jung
full_name: Chen, Ke-Jung
last_name: Chen
- first_name: Sunmyon
full_name: Chon, Sunmyon
last_name: Chon
- first_name: Andrea
full_name: Ferrara, Andrea
last_name: Ferrara
- first_name: Simon C. O.
full_name: Glover, Simon C. O.
last_name: Glover
- first_name: Lionel
full_name: Haemmerlé, Lionel
last_name: Haemmerlé
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
- first_name: Tilman
full_name: Hartwig, Tilman
last_name: Hartwig
- first_name: Alexander
full_name: Heger, Alexander
last_name: Heger
- first_name: Shingo
full_name: Hirano, Shingo
last_name: Hirano
- first_name: Takashi
full_name: Hosokawa, Takashi
last_name: Hosokawa
- first_name: Kohei
full_name: Inayoshi, Kohei
last_name: Inayoshi
- first_name: Ralf S.
full_name: Klessen, Ralf S.
last_name: Klessen
- first_name: Chiaki
full_name: Kobayashi, Chiaki
last_name: Kobayashi
- first_name: Filippos
full_name: Koliopanos, Filippos
last_name: Koliopanos
- first_name: Muhammad A.
full_name: Latif, Muhammad A.
last_name: Latif
- first_name: Yuexing
full_name: Li, Yuexing
last_name: Li
- first_name: Lucio
full_name: Mayer, Lucio
last_name: Mayer
- first_name: Mar
full_name: Mezcua, Mar
last_name: Mezcua
- first_name: Priyamvada
full_name: Natarajan, Priyamvada
last_name: Natarajan
- first_name: Fabio
full_name: Pacucci, Fabio
last_name: Pacucci
- first_name: Martin J.
full_name: Rees, Martin J.
last_name: Rees
- first_name: John A.
full_name: Regan, John A.
last_name: Regan
- first_name: Yuya
full_name: Sakurai, Yuya
last_name: Sakurai
- first_name: Stefania
full_name: Salvadori, Stefania
last_name: Salvadori
- first_name: Raffaella
full_name: Schneider, Raffaella
last_name: Schneider
- first_name: Marco
full_name: Surace, Marco
last_name: Surace
- first_name: Takamitsu L.
full_name: Tanaka, Takamitsu L.
last_name: Tanaka
- first_name: Daniel J.
full_name: Whalen, Daniel J.
last_name: Whalen
- first_name: Naoki
full_name: Yoshida, Naoki
last_name: Yoshida
citation:
ama: 'Woods TE, Agarwal B, Bromm V, et al. Titans of the early universe: The prato
statement on the origin of the first supermassive black holes. Publications
of the Astronomical Society of Australia. 2019;36. doi:10.1017/pasa.2019.14'
apa: 'Woods, T. E., Agarwal, B., Bromm, V., Bunker, A., Chen, K.-J., Chon, S., …
Yoshida, N. (2019). Titans of the early universe: The prato statement on the origin
of the first supermassive black holes. Publications of the Astronomical Society
of Australia. Cambridge University Press. https://doi.org/10.1017/pasa.2019.14'
chicago: 'Woods, Tyrone E., Bhaskar Agarwal, Volker Bromm, Andrew Bunker, Ke-Jung
Chen, Sunmyon Chon, Andrea Ferrara, et al. “Titans of the Early Universe: The
Prato Statement on the Origin of the First Supermassive Black Holes.” Publications
of the Astronomical Society of Australia. Cambridge University Press, 2019.
https://doi.org/10.1017/pasa.2019.14.'
ieee: 'T. E. Woods et al., “Titans of the early universe: The prato statement
on the origin of the first supermassive black holes,” Publications of the Astronomical
Society of Australia, vol. 36. Cambridge University Press, 2019.'
ista: 'Woods TE, Agarwal B, Bromm V, Bunker A, Chen K-J, Chon S, Ferrara A, Glover
SCO, Haemmerlé L, Haiman Z, Hartwig T, Heger A, Hirano S, Hosokawa T, Inayoshi
K, Klessen RS, Kobayashi C, Koliopanos F, Latif MA, Li Y, Mayer L, Mezcua M, Natarajan
P, Pacucci F, Rees MJ, Regan JA, Sakurai Y, Salvadori S, Schneider R, Surace M,
Tanaka TL, Whalen DJ, Yoshida N. 2019. Titans of the early universe: The prato
statement on the origin of the first supermassive black holes. Publications of
the Astronomical Society of Australia. 36, e027.'
mla: 'Woods, Tyrone E., et al. “Titans of the Early Universe: The Prato Statement
on the Origin of the First Supermassive Black Holes.” Publications of the Astronomical
Society of Australia, vol. 36, e027, Cambridge University Press, 2019, doi:10.1017/pasa.2019.14.'
short: T.E. Woods, B. Agarwal, V. Bromm, A. Bunker, K.-J. Chen, S. Chon, A. Ferrara,
S.C.O. Glover, L. Haemmerlé, Z. Haiman, T. Hartwig, A. Heger, S. Hirano, T. Hosokawa,
K. Inayoshi, R.S. Klessen, C. Kobayashi, F. Koliopanos, M.A. Latif, Y. Li, L.
Mayer, M. Mezcua, P. Natarajan, F. Pacucci, M.J. Rees, J.A. Regan, Y. Sakurai,
S. Salvadori, R. Schneider, M. Surace, T.L. Tanaka, D.J. Whalen, N. Yoshida, Publications
of the Astronomical Society of Australia 36 (2019).
date_created: 2024-09-05T09:57:20Z
date_published: 2019-08-06T00:00:00Z
date_updated: 2024-09-12T13:20:41Z
day: '06'
doi: 10.1017/pasa.2019.14
extern: '1'
external_id:
arxiv:
- '1810.12310'
intvolume: ' 36'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: ' https://doi.org/10.48550/arXiv.1810.12310'
month: '08'
oa: 1
oa_version: Preprint
publication: Publications of the Astronomical Society of Australia
publication_identifier:
issn:
- 1323-3580
- 1448-6083
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Titans of the early universe: The prato statement on the origin of the first
supermassive black holes'
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 36
year: '2019'
...