The optical identifcation of events with poorly defined locations: The case of the Fermi GBM GRB140801A

We report the early discovery of the optical afterglow of gamma-ray burst (GRB) 140801A in the 137 deg$^2$ 3-$\sigma$ error-box of the Fermi Gamma-ray Burst Monitor (GBM). MASTER is the only observatory that automatically react to all Fermi alerts. GRB 140801A is one of the few GRBs whose optical counterpart was discovered solely from its GBM localization. The optical afterglow of GRB 140801A was found by MASTER Global Robotic Net 53 sec after receiving the alert, making it the fastest optical detection of a GRB from a GBM error-box. Spectroscopy obtained with the 10.4-m Gran Telescopio Canarias and the 6-m BTA of SAO RAS reveals a redshift of $z=1.32$. We performed optical and near-infrared photometry of GRB 140801A using different telescopes with apertures ranging from 0.4-m to 10.4-m. GRB 140801A is a typical burst in many ways. The rest-frame bolometric isotropic energy release and peak energy of the burst is $E_\mathrm{iso} = 5.54_{-0.24}^{+0.26} \times 10^{52}$ erg and $E_\mathrm{p, rest}\simeq280$ keV, respectively, which is consistent with the Amati relation. The absence of a jet break in the optical light curve provides a lower limit on the half-opening angle of the jet $\theta=6.1$ deg. The observed $E_\mathrm{peak}$ is consistent with the limit derived from the Ghirlanda relation. The joint Fermi GBM and Konus-Wind analysis shows that GRB 140801A could belong to the class of intermediate duration. The rapid detection of the optical counterpart of GRB 140801A is especially important regarding the upcoming experiments with large coordinate error-box areas.Comment: in press MNRAS, 201

Prompt, early, and afterglow optical observations of five gamma-ray bursts (GRBs 100901A, 100902A, 100905A, 100906A, and 101020A)

We present results of the prompt, early, and afterglow optical observations of five gamma-ray bursts, GRBs 100901A, 100902A, 100905A, 100906A, and 101020A, made with the Mobile Astronomical System of TElescope-Robots in Russia (MASTER-II net), the 1.5-m telescope of Sierra-Nevada Observatory, and the 2.56-m Nordic Optical Telescope. For two sources, GRB 100901A and GRB 100906A, we detected optical counterparts and obtained light curves starting before cessation of gamma-ray emission, at 113 s and 48 s after the trigger, respectively. Observations of GRB 100906A were conducted with two polarizing filters. Observations of the other three bursts gave the upper limits on the optical flux; their properties are briefly discussed. More detailed analysis of GRB 100901A and GRB 100906A supplemented by Swift data provides the following results and indicates different origins of the prompt optical radiation in the two bursts. The light curves patterns and spectral distributions suggest a common production site of the prompt optical and high-energy emission in GRB 100901A. Results of spectral fits for GRB 100901A in the range from the optical to X-rays favor power-law energy distributions with similar values of the optical extinction in the host galaxy. GRB 100906A produced a smoothly peaking optical light curve suggesting that the prompt optical radiation in this GRB originated in a front shock. This is supported by a spectral analysis. We have found that the Amati and Ghirlanda relations are satisfied for GRB 100906A. An upper limit on the value of the optical extinction on the host of GRB 100906A is obtained.Comment: 18 pages, 14 figures, 14 tables, 5 machine readable tables; accepted for publication in MNRA

The MASTER-II network of robotic optical telescopes. First results

The main stages in the creation of the Russian segment of the MASTER network of robotic telescopes is described. This network is designed for studies of the prompt optical emission of gammaray bursts (GRBs; optical emission synchronous with the gamma-ray radiation) and surveys of the sky aimed at discovering uncataloged objects and photometric studies for various programs. The first results obtained by the network, during its construction and immediately after its completion in December 2010, are presented. Eighty-nine alert pointings at GRBs (in most cases, being the first ground telescopes to point at the GRBs) were made from September 2006 through July 2011. The MASTER network holds first place in the world in terms of the total number of first pointings, and currently more than half of first pointings at GRBs by ground telescopes are made by the MASTER network. Photometric light curves of GRB 091020, GRB 091127, GRB 100901A, GRB 100906A, GRB 10925A, GRB 110106A, GRB 110422A, and GRB 110530A are presented. It is especially important that prompt emission was observed for GRB 100901A and GRB 100906A, and thar GRB 091127, GRB 110422A, and GRB 110106A were observed from the first seconds in two polarizations. Very-wide-field cameras carried out synchronous observations of the prompt emission of GRB 081102, GRB 081130B, GRB 090305B, GRB 090320B, GRB 090328, and GRB 090424. Discoveries of Type Ia supernovae are ongoing (among them the brightest supernova in 2009): 2008gy, 2009nr, 2010V, and others. In all, photometry of 387 supernovae has been carried out, 43 of which were either discovered or first observed with MASTER telescopes; more than half of these are Type Ia supernovae. Photometric studies of the open clusters NGC 7129 and NGC 7142 have been conducted, leading to the discovery of 38 variable stars. Sixty-nine optical transients have been discovered. © 2013 Pleiades Publishing, Ltd

TOI-1259Ab - A Gas Giant Planet with 2.7 Per Cent Deep Transits and a Bound white Dwarf Companion

We present TOI-1259Ab, a 1.0RJup gas giant planet transiting a 0.71R⊙ K-dwarf on a 3.48 d orbit. The system also contains a bound white dwarf companion TOI-1259B with a projected distance of ∼1600 au from the planet host. Transits are observed in nine TESS sectors and are 2.7 per cent deep - among the deepest known - making TOI-1259Ab a promising target for atmospheric characterization. Our follow-up radial velocity measurements indicate a variability of semiamplitude $K=71\, \rm m\, s^{-1}$, implying a planet mass of 0.44MJup. By fitting the spectral energy distribution of the white dwarf, we derive a total age of $4.08^{+1.21}_{-0.53}$ Gyr for the system. The K dwarf's light curve reveals rotational variability with a period of 28 d, which implies a gyrochronology age broadly consistent with the white dwarf's total age. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.Fellow of the Swiss National Science Foundation

Another Shipment of Six Short-Period Giant Planets from TESS

We present the discovery and characterization of six short-period, transiting giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS) -- TOI-1811 (TIC 376524552), TOI-2025 (TIC 394050135), TOI-2145 (TIC 88992642), TOI-2152 (TIC 395393265), TOI-2154 (TIC 428787891), & TOI-2497 (TIC 97568467). All six planets orbit bright host stars (8.9 <G< 11.8, 7.7 <K< 10.1). Using a combination of time-series photometric and spectroscopic follow-up observations from the TESS Follow-up Observing Program (TFOP) Working Group, we have determined that the planets are Jovian-sized (R$_{P}$ = 1.00-1.45 R$_{J}$), have masses ranging from 0.92 to 5.35 M$_{J}$, and orbit F, G, and K stars (4753 $<$ T$_{eff}$ $<$ 7360 K). We detect a significant orbital eccentricity for the three longest-period systems in our sample: TOI-2025 b (P = 8.872 days, $e$ = $0.220\pm0.053$), TOI-2145 b (P = 10.261 days, $e$ = $0.182^{+0.039}_{-0.049}$), and TOI-2497 b (P = 10.656 days, $e$ = $0.196^{+0.059}_{-0.053}$). TOI-2145 b and TOI-2497 b both orbit subgiant host stars (3.8 $<$ $\log$ g $<$4.0), but these planets show no sign of inflation despite very high levels of irradiation. The lack of inflation may be explained by the high mass of the planets; $5.35^{+0.32}_{-0.35}$ M$_{\rm J}$ (TOI-2145 b) and $5.21\pm0.52$ M$_{\rm J}$ (TOI-2497 b). These six new discoveries contribute to the larger community effort to use {\it TESS} to create a magnitude-complete, self-consistent sample of giant planets with well-determined parameters for future detailed studies.Comment: 20 Pages, 6 Figures, 8 Tables, Accepted by MNRA

Another shipment of six short-period giant planets from TESS

We present the discovery and characterization of six short-period, transiting giant planets from NASA’s Transiting Exoplanet Survey Satellite (TESS) – TOI-1811 (TIC 376524552), TOI-2025 (TIC 394050135), TOI-2145 (TIC 88992642), TOI-2152 (TIC 395393265), TOI-2154 (TIC 428787891), and TOI-2497 (TIC 97568467). All six planets orbit bright host stars (8.9 &lt;G &lt; 11.8, 7.7 &lt;K &lt; 10.1). Using a combination of time-series photometric and spectroscopic follow-up observations from the TESS Follow-up Observing Program Working Group, we have determined that the planets are Jovian-sized (RP = 0.99–1.45 RJ), have masses ranging from 0.92 to 5.26 MJ, and orbit F, G, and K stars (4766 ≤ Teff ≤ 7360 K). We detect a significant orbital eccentricity for the three longest-period systems in our sample: TOI-2025 b (P = 8.872 d, 0.394+0.035-0.038), TOI-2145 b (P = 10.261 d, e = 0.208+0.034-0.047), and TOI-2497 b (P = 10.656 d, e = 0.195+0.043-0.040). TOI-2145 b and TOI-2497 b both orbit subgiant host stars (3.8 &lt; log g &lt;4.0), but these planets show no sign of inflation despite very high levels of irradiation. The lack of inflation may be explained by the high mass of the planets; 5.26+0.38-0.37 MJ (TOI-2145 b) and 4.82 ± 0.41 MJ (TOI-2497 b). These six new discoveries contribute to the larger community effort to use TESS to create a magnitude-complete, self-consistent sample of giant planets with well-determined parameters for future detailed studies. © 2023 The Author(s).80NSSC20K0250; LE140100050; FEUZ-2020-0038, PGC2018-098153-B-C31; National Science Foundation, NSF: 1516242, 1608203, 2007811, AST-1751874, AST-1907790; David and Lucile Packard Foundation, DLPF; National Aeronautics and Space Administration, NASA: GN-2018B-LP-101, NNX13AM97A, XRP 80NSSC22K0233; W. M. Keck Foundation, WMKF; New York Community Trust, NYCT; Research Corporation for Science Advancement, RCSA; Pennsylvania Space Grant Consortium, PSGC; Ames Research Center, ARC; George Mason University, GMU; University of North Carolina, UNC; Massachusetts Institute of Technology, MIT; University of Pennsylvania; Ohio State University, OSU; California Institute of Technology, CIT; University of Florida, UF; Michigan State University, MSU; University of North Carolina at Chapel Hill, UNC-CH; Pennsylvania State University, PSU; University of Montana, UM; University of Texas at Austin, UT; Smithsonian Astrophysical Observatory, SAO; Horizon 2020 Framework Programme, H2020: 1952545, 724427; Mt. Cuba Astronomical Foundation; Accelerated Bridge Construction University Transportation Center, ABC-UTC; National Centres of Competence in Research SwissMAP; Diabetes Patient Advocacy Coalition, DPAC; European Research Council, ERC; European Space Agency, ESA; Australian Research Council, ARC: DP180100972, DP210103119, DP220100365, FL220100117, LE160100001; Deutsche Forschungsgemeinschaft, DFG: HA 3279/12-1, SPP1992; Japan Society for the Promotion of Science, KAKEN: JP18H05439; University of New South Wales, UNSW; University of Southern Queensland, USQ; Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT: 11200751, 1210718, 14ENI2-26865, IC120009; Core Research for Evolutional Science and Technology, CREST: JPMJCR1761; Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2020-780, N13.1902.21.0039; Ministério da Ciência, Tecnologia e Inovação, MCTI; University of Toronto, U of T; Université de Genève, UNIGE; Ministry of Economy; Nanjing University, NJU; Instituto de Astrofísica de Canarias, IAC; NCCR Catalysis, NCCRThe authors thank the CHIRON team members, including Todd Henry, Leonardo Paredes, Hodari James, Azmain Nisak, Rodrigo Hinojosa, Roberto Aviles, Wei-Chun Jao, and CTIO staffs, for their work in acquiring RVs with CHIRON at CTIO. This research has made use of SAO/NASA’s Astrophysics Data System Bibliographic Services. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. This work has made use of data from the European Space Agency (ESA) mission Gaia ( https://www.cosmos.esa.int/gaia ), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium ). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work makes use of observations from the LCO network. Based in part on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovações (MCTI/LNA) do Brasil, the US National Science Foundation’s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).Funding for the TESS mission is provided by NASA’s Science Mission directorate. The authors acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the NASA Exoplanet Archive and the Exoplanet Follow-up Observation Program website, which are operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). This paper includes observations obtained under Gemini program GN-2018B-LP-101. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This publication makes use of The Data and Analysis Center for Exoplanets (DACE), which is a facility based at the University of Geneva (CH) dedicated to extrasolar planets data visualisation, exchange and analysis. DACE is a platform of the Swiss National Centre of Competence in Research (NCCR) PlanetS, federating the Swiss expertise in Exoplanet research. The DACE platform is available at https://dace.unige.ch .LC, KS, EA, JR, JER, JAR, PW, and EZ are grateful for support from NSF grants AST-1751874 and AST-1907790, along with a Cottrell Fellowship from the Research Corporation. CZ is supported by a Dunlap Fellowship at the Dunlap Institute for Astronomy & Astrophysics, funded through an endowment established by the Dunlap family and the University of Toronto. T.H. acknowledges support from the European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins 83 24 28. JVS acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project Four Aces; grant agreement No. 724427). PR acknowledges support from NSF grant No. 1952545. RB and AJ acknowledges support from FONDECYT Projects 11200751 and 1210718 and from the CORFO project N◦14ENI2-26865. AJ, RB and MH acknowledge support from project IC120009 ‘Millennium Institute of Astrophysics (MAS)’ of the Millenium Science Initiative, Chilean Ministry of Economy. The Pennsylvania State University Eberly College of Science. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. KKM gratefully acknowledges support from the New York Community Trust’s Fund for Astrophysical Research. LG and AG are supported by NASA Massachusetts Space Grant Fellowships. EWG, ME, and PC acknowledge support by Deutsche Forschungsgemeinschaft (DFG) grant HA 3279/12-1 within the DFG Schwerpunkt SPP1992, Exploring the Diversity of Extrasolar Planets. BSG was partially supported by the Thomas Jefferson Chair for Space Exploration at the Ohio State University. CD acknowledges support from the Hellman Fellows Fund and NASA XRP via grant 80NSSC20K0250. BSS, MVG, and AAB acknowledge the support of Ministry of Science and Higher Education of the Russian Federation under the grant 075-15-2020-780 (N13.1902.21.0039). BA is supported by Australian Research Council Discovery Grant DP180100972. TRB acknowledges support from the Australian Research Council (DP210103119). TRB acknowledges support from the Australian Research Council (DP210103119 and FL220100117). The authors thank the CHIRON team members, including Todd Henry, Leonardo Paredes, Hodari James, Azmain Nisak, Rodrigo Hinojosa, Roberto Aviles, Wei-Chun Jao, and CTIO staffs, for their work in acquiring RVs with CHIRON at CTIO. This research has made use of SAO/NASA’s Astrophysics Data System Bibliographic Services. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work makes use of observations from the LCO network. Based in part on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovações (MCTI/LNA) do Brasil, the US National Science Foundation’s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). Funding for the TESS mission is provided by NASA’s Science Mission directorate. The authors acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the NASA Exoplanet Archive and the Exoplanet Follow-up Observation Program website, which are operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). This paper includes observations obtained under Gemini program GN-2018B-LP-101. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This publication makes use of The Data and Analysis Center for Exoplanets (DACE), which is a facility based at the University of Geneva (CH) dedicated to extrasolar planets data visualisation, exchange and analysis. DACE is a platform of the Swiss National Centre of Competence in Research (NCCR) PlanetS, federating the Swiss expertise in Exoplanet research. The DACE platform is available at https://dace.unige.ch. MINERVA-Australis is supported by Australian Research Council LIEF Grant LE160100001 (Discovery Grant DP180100972 and DP220100365) Mount Cuba Astronomical Foundation, and institutional partners University of Southern Queensland, UNSW Sydney, MIT, Nanjing University, George Mason University, University of Louisville, University of California Riverside, University of Florida, and The University of Texas at Austin. The authors respectfully acknowledge the traditional custodians of all lands throughout Australia and recognize their continued cultural and spiritual connection to the land, waterways, cosmos, and community. The authors pay our deepest respects to all Elders, ancestors and descendants of the Giabal, Jarowair, and Kambuwal nations, upon whose lands the MINERVA-Australis facility at Mt Kent is situated. MINERVA-North is a collaboration among the Harvard-Smithsonian Center for Astrophysics, The Pennsylvania State University, the University of Montana, the University of Southern Queensland, University of Pennsylvania, and George Mason University. It is made possible by generous contributions from its collaborating institutions and Mt. Cuba Astronomical Foundation, The David & Lucile Packard Foundation, National Aeronautics and Space Administration (EPSCOR grant NNX13AM97A, XRP 80NSSC22K0233), the Australian Research Council (LIEF grant LE140100050), and the National Science Foundation (grants 1516242, 1608203, and 2007811). This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. This work is partly financed by the Spanish Ministry of Economics and Competitiveness through grants PGC2018-098153-B-C31.The work of VK was supported by the Ministry of science and higher education of the Russian Federation, topic FEUZ-2020-0038. This work is partly supported by JSPS KAKENHI Grant Number JP18H05439, JST CREST Grant Number JPMJCR1761. This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide.Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. This work is partly financed by the Spanish Ministry of Economics and Competitiveness through grants PGC2018-098153-B-C31.The work of VK was supported by the Ministry of science and higher education of the Russian Federation, topic FEUZ-2020-0038.LC, KS, EA, JR, JER, JAR, PW, and EZ are grateful for support from NSF grants AST-1751874 and AST-1907790, along with a Cottrell Fellowship from the Research Corporation. CZ is supported by a Dunlap Fellowship at the Dunlap Institute for Astronomy & Astrophysics, funded through an endowment established by the Dunlap family and the University of Toronto. T.H. acknowledges support from the European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins 83 24 28. JVS acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project Four Aces; grant agreement No. 724427). PR acknowledges support from NSF grant No. 1952545. RB and AJ acknowledges support from FONDECYT Projects 11200751 and 1210718 and from the CORFO project N°14ENI2-26865. AJ, RB and MH acknowledge support from project IC120009 ‘Millennium Institute of Astrophysics (MAS)’ of the Millenium Science Initiative, Chilean Ministry of Economy. The Pennsylvania State University Eberly College of Science. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. KKM gratefully acknowledges support from the New York Community Trust’s Fund for Astrophysical Research. LG and AG are supported by NASA Massachusetts Space Grant Fellowships. EWG, ME, and PC acknowledge support by Deutsche Forschungsgemeinschaft (DFG) grant HA 3279/12-1 within the DFG Schwerpunkt SPP1992, Exploring the Diversity of Extrasolar Planets. BSG was partially supported by the Thomas Jefferson Chair for Space Exploration at the Ohio State University. CD acknowledges support from the Hellman Fellows Fund and NASA XRP via grant 80NSSC20K0250. BSS, MVG, and AAB acknowledge the support of Ministry of Science and Higher Education of the Russian Federation under the grant 075-15-2020-780 (N13.1902.21.0039). BA is supported by Australian Research Council Discovery Grant DP180100972. TRB acknowledges support from the Australian Research Council (DP210103119). TRB acknowledges support from the Australian Research Council (DP210103119 and FL220100117).Minerva -Australis is supported by Australian Research Council LIEF Grant LE160100001 (Discovery Grant DP180100972 and DP220100365) Mount Cuba Astronomical Foundation, and institutional partners University of Southern Queensland, UNSW Sydney, MIT, Nanjing University, George Mason University, University of Louisville, University of California Riverside, University of Florida, and The University of Texas at Austin. The authors respectfully acknowledge the traditional custodians of all lands throughout Australia and recognize their continued cultural and spiritual connection to the land, waterways, cosmos, and community. The authors pay our deepest respects to all Elders, ancestors and descendants of the Giabal, Jarowair, and Kambuwal nations, upon whose lands the Minerva -Australis facility at Mt Kent is situated.MINERVA-North is a collaboration among the Harvard-Smithsonian Center for Astrophysics, The Pennsylvania State University, the University of Montana, the University of Southern Queensland, University of Pennsylvania, and George Mason University. It is made possible by generous contributions from its collaborating institutions and Mt. Cuba Astronomical Foundation, The David & Lucile Packard Foundation, National Aeronautics and Space Administration (EPSCOR grant NNX13AM97A, XRP 80NSSC22K0233), the Australian Research Council (LIEF grant LE140100050), and the National Science Foundation (grants 1516242, 1608203, and 2007811)

TOI-1259Ab – a gas giant planet with 2.7 per cent deep transits and a bound white dwarf companion

We present TOI-1259Ab, a 1.0RJup gas giant planet transiting a 0.71R⊙ K-dwarf on a 3.48 d orbit. The system also contains a bound white dwarf companion TOI-1259B with a projected distance of ∼1600 au from the planet host. Transits are observed in nine TESS sectors and are 2.7 per cent deep – among the deepest known – making TOI-1259Ab a promising target for atmospheric characterization. Our follow-up radial velocity measurements indicate a variability of semiamplitude $K=71\, \rm m\, s^{-1}$, implying a planet mass of 0.44MJup. By fitting the spectral energy distribution of the white dwarf, we derive a total age of $4.08^{+1.21}_{-0.53}$ Gyr for the system. The K dwarf’s light curve reveals rotational variability with a period of 28 d, which implies a gyrochronology age broadly consistent with the white dwarf’s total age