{"title":"Superstatistics and stellar rotation: Modeling velocity distributions in six stellar groups","authors":"Mahsa Iranmanesh , Hamid Arjomand Kermani , Kamel Ourabah","doi":"10.1016/j.newast.2025.102408","DOIUrl":"10.1016/j.newast.2025.102408","url":null,"abstract":"<div><div>In the present study, we investigate the observed distribution of the projected rotational velocity for six different stellar groups: young-type and late-type (including the spectral classes F, G, and K), OB-type, A-type, B-type, and M-type. Our analysis shows that the distribution of projected rotational velocities for these stellar groups deviates from a Maxwellian distribution. Instead, it is better captured by a generalized statistical mechanics framework known as superstatistics. Within this framework, the distribution is modeled as a superposition of a locally Maxwellian distribution, whose width fluctuates over a large spatiotemporal scale according to a <span><math><msup><mrow><mi>χ</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> distribution. We identify a correlation between the mean rotational velocity and the parameters defining the distribution, specifically the number of degrees of freedom contributing to the fluctuations. This dependency highlights the intricate relationship between the rotational dynamics and the generalized statistical mechanics properties of stellar systems.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102408"},"PeriodicalIF":1.9,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-28DOI: 10.1016/j.newast.2025.102407
Xiaoming Li , Yueyan Tao , Xiaochen Li , Shijun Liao
{"title":"A numerical scheme to obtain periodic three-body orbits with finite angular momentum","authors":"Xiaoming Li , Yueyan Tao , Xiaochen Li , Shijun Liao","doi":"10.1016/j.newast.2025.102407","DOIUrl":"10.1016/j.newast.2025.102407","url":null,"abstract":"<div><div>The three-body problem is ubiquitous in various physical systems. Thousands of periodic orbits for the three-body problem with zero angular momentum were obtained in recent years. In this paper, we present a numerical scheme to obtain periodic orbits for the three-body problem with finite angular momentum. The proposed approach combines a continuation method and the Newton–Raphson method, which are implemented using Clean Numerical Simulation (CNS) for the integration of the equations of motion. The figure-eight periodic orbit and another newly found periodic orbit are taken to generate periodic orbits by continuously varying the angular momentum. The linear stability of these periodic orbits are investigated through Floquet theory. It is suggested that angular momentum plays a significant role in influencing the linear instability of periodic orbits. Our proposed numerical approach inspires the further research in the intricate dependence of the periodic orbits on the angular momentum, providing a powerful tool for investigating the nonlinear dynamics of the three-body problem.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102407"},"PeriodicalIF":1.9,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-21DOI: 10.1016/j.newast.2025.102406
Marek Wolf , Petr Zasche , Miloslav Zejda , Martin Mašek , Andrej Mudray , Hana Kučáková , Waldemar Ogłoza , Jaroslav Merc , Jan Kára , Vojtěch Dienstbier
{"title":"TESS light curves and period changes in low-mass eclipsing binary BB Persei","authors":"Marek Wolf , Petr Zasche , Miloslav Zejda , Martin Mašek , Andrej Mudray , Hana Kučáková , Waldemar Ogłoza , Jaroslav Merc , Jan Kára , Vojtěch Dienstbier","doi":"10.1016/j.newast.2025.102406","DOIUrl":"10.1016/j.newast.2025.102406","url":null,"abstract":"<div><div>We present a detailed analysis of the low-mass detached eclipsing binary system BB Persei, which contains two K-type stars in a circular orbit with a short period of 0.4856 d. We used light curves from the Transiting Exoplanet Survey Satellite (<span>Tess</span>), which observed BB Per in five sectors, to determine its photometric properties and a precise orbital ephemeris. The solution of the <span>Tess</span> light curve in <span>Phoebe</span> results in a detached configuration, where the temperature of the primary component was fixed to <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>5</mn><mspace></mspace><mn>300</mn></mrow></math></span> K according to <span>Lamost</span>, which gives us <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>5</mn><mspace></mspace><mn>050</mn><mo>±</mo><mn>50</mn></mrow></math></span> K for the secondary. The spectral type of the primary component was derived as K0 and the photometric mass ratio was estimated <span><math><mrow><mi>q</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>90</mn></mrow></math></span>. Slow period changes on the current O-C diagram spanning the past 25 years indicate the presence of a third body orbiting the eclipsing pair with an orbital period of about 22 years. The companion could be a red dwarf of spectral type M6–M7 with a minimal mass of about 0.1 M<span><math><msub><mrow></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>. The characteristics and temporal variation of the dark region on the surface of the secondary component were estimated.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102406"},"PeriodicalIF":1.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-17DOI: 10.1016/j.newast.2025.102405
João L. Yun , Pedro M. Martins , Gorka Zubiri-Elso , Anlaug Amanda Djupvik
{"title":"The young stellar cluster towards IRAS 03523+5343","authors":"João L. Yun , Pedro M. Martins , Gorka Zubiri-Elso , Anlaug Amanda Djupvik","doi":"10.1016/j.newast.2025.102405","DOIUrl":"10.1016/j.newast.2025.102405","url":null,"abstract":"<div><div>We present a study of the star formation occurring in the most active region of a molecular cloud in the second quadrant of the (outer) Galaxy towards IRAS 03523+5343. Near-infrared <span><math><mrow><mi>J</mi><mi>H</mi><msub><mrow><mi>K</mi></mrow><mrow><mi>S</mi></mrow></msub></mrow></math></span> images and <span><math><mi>K</mi></math></span>-band spectroscopy were obtained with NOTCam at the Nordic Optical Telescope at the Roque de Los Muchachos Observatory. Mid-infrared <em>WISE</em> satellite images and submm <em>JCMT/SCUBA-2</em> catalogue sources were also explored. In addition, millimetre line CS spectra were obtained with the Yebes 40 m telescope.</div><div>Within the region of the molecular cloud covered by our CS <span><math><mrow><mo>(</mo><mi>J</mi><mo>=</mo><mn>1</mn><mo>−</mo><mn>0</mn><mo>)</mo></mrow></math></span> maps, the line is strong and extends over all the mapped region of <span><math><mrow><mn>3</mn><mo>.</mo><msup><mrow><mn>7</mn></mrow><mrow><mo>′</mo></mrow></msup><mo>×</mo><mn>3</mn><mo>.</mo><msup><mrow><mn>7</mn></mrow><mrow><mo>′</mo></mrow></msup></mrow></math></span>. This high-density molecular gas defines a molecular core exhibiting an angular size FWHM of about <span><math><msup><mrow><mn>1</mn></mrow><mrow><mo>′</mo></mrow></msup></math></span> (0.7 pc at 2.4 kpc distance). We estimate a lower limit to the mass of the molecular gas in this region to be about 995 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>. A SCUBA-2 core was detected with an estimated total mass of 250 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>.</div><div>We identify a young stellar cluster with a few hundred sources with colours compatible to YSOs at the location of a strong enhancement of the stellar density coincident with the IRAS position. The main counterpart of the IRAS source is a very red and bright source with radio jets likely to be a high-mass young stellar object. A second bright source is a Herbig Be candidate source displaying a blue nebula with a morphology that suggests the dissipation of a collimated flow.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102405"},"PeriodicalIF":1.9,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-15DOI: 10.1016/j.newast.2025.102391
Shuang Wang, Yuangui Yang, Huiyu Yuan, Ligang Yu
{"title":"CCD photometric studies of two Primitive C-type main-belt asteroids: (51) Nemausa and (52) Europa","authors":"Shuang Wang, Yuangui Yang, Huiyu Yuan, Ligang Yu","doi":"10.1016/j.newast.2025.102391","DOIUrl":"10.1016/j.newast.2025.102391","url":null,"abstract":"<div><div>We present new CCD photometry for primitive C-type main-belt asteroids (51) Nemausa and (52) Europa performed on several nights of 2016, by using the 60-cm telescope at Xinglong station of NAOC. From our new data, the rotation periods are determined as 7.784840 h for (51) Nemausa and 5.629960 h for (52) Europa. Based on the convex inversion method, the pole ambiguity was removed, and we refined pole directions and triaxial ratios as follows, (168 °, <span><math><mrow><mo>−</mo><mn>6</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span>) with <span><math><mrow><mi>a</mi><mo>/</mo><mi>b</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>09</mn></mrow></math></span> and <span><math><mrow><mi>b</mi><mo>/</mo><mi>c</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>03</mn></mrow></math></span> for (51) Nemausa, and a pole is derived as (256°, 32°) with <span><math><mrow><mi>a</mi><mo>/</mo><mi>b</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>04</mn></mrow></math></span> and <span><math><mrow><mi>b</mi><mo>/</mo><mi>c</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>33</mn></mrow></math></span> for (52) Europa. From the parameters of 49 asteroids, a statistic study was carried out. All these results will help us to understand the physical properties of pristine small objects in the solar system.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102391"},"PeriodicalIF":1.9,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-14DOI: 10.1016/j.newast.2025.102393
Shyam Das , Saibal Ray , Amit Das , Shyamal Kumar Pal
{"title":"Anisotropic compact stellar models under the condition of zero complexity","authors":"Shyam Das , Saibal Ray , Amit Das , Shyamal Kumar Pal","doi":"10.1016/j.newast.2025.102393","DOIUrl":"10.1016/j.newast.2025.102393","url":null,"abstract":"<div><div>In this article, we introduce a new exact solution of the Einstein field equations that characterizes static, spherically symmetric anisotropic compact stars. In our approach the solution of the system of field equations have been obtained under the constraint of vanishing complexity, in addition to specifying the metric potential corresponding to the <span><math><msub><mrow><mi>g</mi></mrow><mrow><mi>r</mi><mi>r</mi></mrow></msub></math></span> component. The class of generalized solutions has been smoothly matched with the Schwarzschild solutions describing the exterior across the boundary. The model parameters are fixed by using this matching conditions and additionally from the condition of the vanishing of the radial pressure at the surface. We have employed recent measurements of the mass and radius from the observed pulsars to validate and justify the physical applicability of our model.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102393"},"PeriodicalIF":1.9,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-13DOI: 10.1016/j.newast.2025.102404
J Praveen, S K Narasimhamurthy
{"title":"The role of Finsler-Randers geometry in shaping anisotropic metrics and thermodynamic properties in black holes theory","authors":"J Praveen, S K Narasimhamurthy","doi":"10.1016/j.newast.2025.102404","DOIUrl":"10.1016/j.newast.2025.102404","url":null,"abstract":"<div><div>In this research paper, we delve into the study of black hole (BH) structure within the context of Finsler geometry, a novel approach not previously explored by other researchers. We focused on developing the Finsler-Randers metric tensor for black holes, with the aid of the Barthel connection along with the osculating Riemannian method. This newly derived metric demonstrates significant departures from the conventional black hole metrics found in General Relativity (GR) by the presence of Finslerian term <span><math><mi>η</mi></math></span>, thereby shedding new light on the geometry and nature of black holes. To comprehensively understand the characteristics of black holes, we calculated the metric components under both vacuum and non-vacuum conditions. Our findings indicate that the metric structure aligns well with the known Riemannian limits, reinforcing the compatibility of our model with established theories. Moreover, we extended our analysis to include the thermodynamics of black holes in a Finslerian framework in brief. The results from this exploration affirm that the fundamental laws of black hole thermodynamics remain valid, reinforcing the viability and consistency of our Finslerian model. This study not only contributes to our understanding of black hole physics but also opens new avenues for further research in the realm of Finsler geometry and its implications for astrophysics<strong>.</strong></div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102404"},"PeriodicalIF":1.9,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-13DOI: 10.1016/j.newast.2025.102401
Marina Afonina , Sergei Popov
{"title":"Evolution of neutron stars in wide eccentric low-mass binary systems","authors":"Marina Afonina , Sergei Popov","doi":"10.1016/j.newast.2025.102401","DOIUrl":"10.1016/j.newast.2025.102401","url":null,"abstract":"<div><div>Precise astrometric measurement with <em>Gaia</em> satellite resulted in the discovery of tens of wide binary systems consisting of a Sun-like star and an invisible component. The latter can be a white dwarf, a neutron star, or a black hole. In this paper, we model magneto-rotational evolution of neutron stars in wide low-mass binaries accounting for the orbital eccentricity. We aim to calculate when neutron stars in such systems can start to accrete matter from the stellar wind of the companion. We show that the transition from the ejector to the propeller stage occurs earlier in more eccentric systems, thus increasing the time that neutron stars can spend accreting matter. Our calculations show that in the case of efficient spin-down at the propeller stage, a neutron star in an eccentric orbit with <span><math><mrow><mi>e</mi><mo>≳</mo><mn>0</mn><mo>.</mo><mn>6</mn></mrow></math></span> and a standard magnetic field <span><math><mrow><mi>B</mi><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>12</mn></mrow></msup></mrow></math></span> G can start accreting within a few Gyr. For neutron stars with <span><math><mrow><mi>B</mi><mo>=</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>13</mn></mrow></msup></mrow></math></span> G the onset of accretion occurs earlier regardless of the orbital eccentricity. Otherwise, with a lower spin-down rate, such a neutron star will remain at the propeller stage for most of its life.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102401"},"PeriodicalIF":1.9,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New AstronomyPub Date : 2025-03-10DOI: 10.1016/j.newast.2025.102392
Y.H.M. Hendy, Ahmed Shokry, Ali Takey, Mohamed S. Aboueisha
{"title":"The first CCD photometric study of the member eclipsing binary ZTF J060425.73+365000.1 in the newly discovered young open cluster UBC 68","authors":"Y.H.M. Hendy, Ahmed Shokry, Ali Takey, Mohamed S. Aboueisha","doi":"10.1016/j.newast.2025.102392","DOIUrl":"10.1016/j.newast.2025.102392","url":null,"abstract":"<div><div>Multi-band photometric observations of the contact binary system ZTF J060425.73+365000.1 (hereinafter ZTF 06+36) are conducted using the 1.88-meter telescope at Kottamia Astronomical Observatory (KAO), Cairo, Egypt. This study presents the first photometric measurements and light curve analysis of this binary system. Analysis using the Wilson-Devinney (W-D) program reveals that the ZTF 06+36 system is an overcontact A-subtype system with a fill-out factor of 0.15 and mass ratios (q) of 0.34. To understand its evolutionary status, we investigated mass-luminosity, mass-radius, and mass-temperature relations. These relations indicate that the primary component of the system is the main sequence star, whereas the less massive component has evolved beyond the main sequence. Additionally, Gaia DR3 data is utilized to analyze the binary system's position on the color-magnitude diagram and evaluate its membership in the open cluster UBC 68. We combined two methods of machine learning algorithms (HDBSCAN and pyUPMASK) to obtain reliable stellar members of the UBC 68. They confirmed that the eclipsing binary</div><div>ZTF 06+36 has a membership probability of 1, indicating it is a member of the cluster. We also determined the physical parameters of the open cluster (UBC 68). Its age log(age), reddening E(BP-RP), and photometric distance are estimated to be 8.41±0.33 yr, 0.46±0.03 mag, and 2259±115 pc, respectively.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102392"},"PeriodicalIF":1.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transit timing variations of the sub-Saturn exoplanet HAT-P-12b","authors":"Kaviya Parthasarathy , Hsin-Min Liu , Ing-Guey Jiang , Li-Chin Yeh , Napaporn A-thano , Supachai Awiphan , Wen-Chi Cheng , Devesh P. Sariya , Shraddha Biswas , Devendra Bisht , Evgeny Griv , David Mkrtichian , Vineet Kumar Mannaday , Parijat Thakur , Aleksey Shlyapnikov","doi":"10.1016/j.newast.2025.102390","DOIUrl":"10.1016/j.newast.2025.102390","url":null,"abstract":"<div><div>We present Transit Timing Variations (TTVs) of HAT-P-12b, a low-density sub-Saturn mass planet orbiting a metal-poor K4 dwarf star. Using 14 years of observational data (2009–2022), our study incorporates 7 new ground-based photometric transit observations, three sectors of Transiting Exoplanet Survey Satellite (TESS) data, and 23 previously published light curves. A total of 46 light curves were analyzed using various analytical models, such as linear, orbital decay, apsidal precession, and sinusoidal models to investigate the presence of additional planets. The stellar tidal quality factor (<span><math><mrow><msubsup><mrow><mi>Q</mi></mrow><mrow><mo>⋆</mo></mrow><mrow><mo>′</mo></mrow></msubsup><mo>∼</mo></mrow></math></span> 28.4) is lower than the theoretical predictions, making the orbital decay model an unlikely explanation. The apsidal precession model with a χ<span><math><msubsup><mrow></mrow><mrow><mi>r</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> of 4.2 revealed a slight orbital eccentricity (e = 0.0013) and a precession rate of 0.0045 rad/epoch. Frequency analysis using the Generalized Lomb–Scargle (GLS) periodogram identified a significant periodic signal at 0.00415 cycles/day (FAP = 5.1 × 10<sup>−6</sup> %), suggesting the influence of an additional planetary companion. The sinusoidal model provides the lowest reduced chi-squared value (χ<span><math><msubsup><mrow></mrow><mrow><mi>r</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>) of 3.2. Sinusoidal fitting of the timing residuals estimated this companion to have a mass of approximately 0.02 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>J</mi></mrow></msub></math></span> , assuming it is in a 2:1 Mean-Motion Resonance (MMR) with HAT-P-12b. Additionally, the Applegate mechanism, with an amplitude much smaller than the observed TTV amplitude of 156 s, confirms that stellar activity is not responsible for the observed variations.</div></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":"119 ","pages":"Article 102390"},"PeriodicalIF":1.9,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}