New Astronomy最新文献

{"title":"Definition of multispectral camera system parameters to model the asteroid 2001 SN263","authors":"","doi":"10.1016/j.newast.2024.102287","DOIUrl":"10.1016/j.newast.2024.102287","url":null,"abstract":"<div><p>In 2012, Brazil began the studies to send its first deep space exploration mission, ASTER, which would be the first mission to orbit a triple asteroid system, 2001 SN263. We aim to contribute to the ASTER mission by defining the parameters of a multispectral camera system that will be used to study the asteroid system 2001 SN263, through software simulations that should help planning the data collection. We inserted the shape model of the objects in the software POV-Ray and modeled two cameras, a Wide Angle (WAC) and a Narrow Angle (NAC). We inserted the asteroid's parameters and simulated the satellite position. We created various scenes so we could obtain a good view of the asteroid. Alpha is entirely visible only in the WAC images, while the NAC is expected to reveal surface details. Beta seems relatively small in the WAC images, whereas we obtain a broad view from the NAC at 100 km distance. Gamma, smaller than Beta, should provide more detailed images through the NAC, whereas the WAC images should be able to show its inclined orbit around Alpha. To see Gamma behind Alpha in its revolution movement, we would have to elevate the camera's orbit. The method employed to simulate images generated by satellite cameras can be applied to other scenarios where the target requires imaging, extending beyond the field of planetary geology.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141712259","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":"Modeling compact stars with two fluids","authors":"","doi":"10.1016/j.newast.2024.102286","DOIUrl":"10.1016/j.newast.2024.102286","url":null,"abstract":"<div><p>In this paper, we study the curved Krori–Barua spacetime geometry to describe compact stars with two components: dark and ordinary matter, using a two-fluid model approach. We choose the equation of state derived from the rotational curves of galaxies for dark matter and the polytropic equation of state for ordinary matter. The physical requirements for a realistic compact star are satisfied using specific parameters. For the polytropic index <span><math><mrow><mi>η</mi><mo>=</mo><mn>2</mn></mrow></math></span>, we find the values of observed masses, reported in our previous investigation (Mafa et al., 2020).</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1384107624001003/pdfft?md5=051c3f9eade0b3342ac0112088c30b75&pid=1-s2.0-S1384107624001003-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141637662","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}

{"title":"The role of radial viscosity force and anisotropic thermal conduction in hot accretion flow","authors":"","doi":"10.1016/j.newast.2024.102276","DOIUrl":"10.1016/j.newast.2024.102276","url":null,"abstract":"<div><p>Recent observational evidence confirms the weak-collision dynamics of hot optically thin accretion flows around Sgr A<span><math><msup><mrow></mrow><mrow><mo>∗</mo></mrow></msup></math></span> and other nearby galactic nuclei. As a result, thermal conduction as a diffusion process can transfer the heat by electrons in a collisionless magnetized plasma. While most of the previous analytical studies consider the azimuthal viscosity, the recent studies indicated that the radial viscosity strongly affects the properties of the advection dominated accretion discs. So, in this paper, we explore the roles of two parts of anisotropic thermal conduction (parallel and perpendicular) and radial viscosity in the hot accretion disc by considering axisymmetric and steady state assumptions in the presence of outflows that can transport energy from accretion disc outward. We use the set of self-similar solutions to solve the basic equations in our present model. Our solutions reveal that transverse thermal conduction as a cooling mechanism, leads to reductions in gas temperature, disc thickness, and accretion velocity of the disc, whereas the disc rotates at a fast rate. Moreover Our solutions indicate that the perpendicular thermal conduction and the radial viscosity have opposite behavior in the physical variables of the disc. Also, our results have indicated that the anisotropic thermal conduction is significant in the parameter space of radial viscosity, outflow in the regions that the physical constraints <span><math><mrow><msub><mrow><mi>t</mi></mrow><mrow><mi>i</mi><mi>n</mi></mrow></msub><mo>≥</mo><msub><mrow><mi>t</mi></mrow><mrow><mo>⊥</mo><mo>,</mo><mi>c</mi><mi>o</mi><mi>n</mi></mrow></msub></mrow></math></span> and <span><math><mrow><msub><mrow><mi>q</mi></mrow><mrow><mo>∥</mo><mo>,</mo><mi>c</mi><mi>o</mi><mi>n</mi></mrow></msub><mo>⩽</mo><msub><mrow><mi>q</mi></mrow><mrow><mo>⊥</mo><mo>,</mo><mi>c</mi><mi>o</mi><mi>n</mi></mrow></msub></mrow></math></span> are satisfied.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141696176","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":"Spectral evolution and photo-ionization analysis of Nova Cas 2020 (V1391 Cas)","authors":"G.M. Hamed ,&nbsp;H.H. Esenoglu ,&nbsp;A.I. Galeev","doi":"10.1016/j.newast.2024.102273","DOIUrl":"https://doi.org/10.1016/j.newast.2024.102273","url":null,"abstract":"<div><p>We present spectroscopic observations of Nova Cas 2020 <strong>(V1391 Cas)</strong> obtained using the Russian Turkish Telescope during different stages of its 2020 outburst. We followed the spectral evolution of the nova until it entered the nebular phase. The expansion velocity of the ejecta reached <span><math><mrow><mo>∼</mo><mn>780</mn><mspace></mspace><msup><mrow><mi>km s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>. The fluxes of the neutral [O I] lines at wavelengths 6300, 6364, and 5577 <span><math><mtext>̊A</mtext></math></span> were used to calculate the electron temperature and the mass of neutral oxygen in the ejecta. We found average values <span><math><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>=</mo><mi>4890</mi><mspace></mspace><mi>K</mi></mrow></math></span>, <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mi>OI</mi></mrow></msub><mo>=</mo><mi>2.54</mi><mo>×</mo><msup><mrow><mi>10</mi></mrow><mrow><mi>−5</mi></mrow></msup><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></mrow></math></span> which are consistent with the values calculated for other novae. We modeled the nova’s ejected envelope 515 days after its discovery and found that the log elemental abundances by number relative to Hydrogen of the envelope are He = −0.7, C = −5.5, O = −2.5, N = −2.0 and Ne = −4.0.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605542","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":"LRS Bianchi type-I with Hubble’s horizon as IR cut-off in f(R) gravity","authors":"Syed Mudassir Syed Iqbal ,&nbsp;G.U. Khapekar ,&nbsp;S.H. Shekh ,&nbsp;A. Dixit","doi":"10.1016/j.newast.2024.102274","DOIUrl":"10.1016/j.newast.2024.102274","url":null,"abstract":"<div><p>we explored the holographic dark energy model using Hubble’s Horizon as the infrared (IR) cut-off in Locally Rotationally Symmetric (LRS) Bianchi type-I, considering the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> gravity framework in our analysis. In order to solve the field equations, we assume a relation <span><math><mrow><mi>F</mi><mo>∝</mo><mspace></mspace><msup><mrow><mi>a</mi></mrow><mrow><mi>m</mi></mrow></msup></mrow></math></span> and volumetric power law expansion (where <span><math><mi>m</mi></math></span> is constant). we have expressed various crucial cosmological parameters in terms of the redshift <span><math><mi>z</mi></math></span> and depicted them graphically to enhance our understanding of the expansion and evolution of the universe like holographic dark energy density (<span><math><msub><mrow><mi>ρ</mi></mrow><mrow><mi>Λ</mi></mrow></msub></math></span>), holographic dark energy pressure (<span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>Λ</mi></mrow></msub></math></span>), equation of state parameter (<span><math><mi>ω</mi></math></span>) , total energy density parameter (<span><math><mi>Ω</mi></math></span>) etc. Also, we analyzed the stability of the universe in our model through the squared speed of sound test and its validity by energy conditions. Ultimately, our model indicates that the universe is currently in an expanding phase, exhibiting an accelerating phase, closely approaching a flat geometry, and its behavior resembles that of a quintessence dark energy model.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587749","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":"New results on the two-body decay of neutrons shed new light on neutron stars","authors":"Eugene Oks","doi":"10.1016/j.newast.2024.102275","DOIUrl":"10.1016/j.newast.2024.102275","url":null,"abstract":"<div><p>In attempts to resolve the neutron lifetime puzzle, there was suggested a hypothetical decay of neutrons into some <em>unspecified</em> dark matter (DM) particles. Later there were performed studies on how the hypothetical decay of neutrons would affect neutron stars. Recently it was shown that with the allowance for the second solution of Dirac equation for hydrogen atoms, the theoretical branching ratio (BR) for the two-body decay of neutrons (compared to their three-body decay) is amplified by a factor of 3300 from 0.000004. So, the BR becomes about 1.3% in the excellent agreement with the “experimental” BR = (1.15 ± 0.27)% required for reconciling the two distinct experimental values of the neutron lifetime: one from the beam experiments, another from the trap experiments. This meant that the two-body decay of neutrons in the beam experiments (that count only the protons) plays a much more sizable part in the overestimation of the lifetime of neutrons in these experiments than previously thought. Hydrogen atoms corresponding to the second solution of Dirac equations are called the second flavor of hydrogen atoms (SFHA) by the analogy with the flavors of quarks. The existence of the SFHA is evidenced by four different types of atomic/molecular experiments. The primary feature of the SFHA is that due to having only the s-states, they do not emit or absorb the electromagnetic radiation (except for the 21 cm line): they are practically <em>dark</em>. The SFHA became a candidate for a part of DM for the first time after the SFHA-based successful qualitative and quantitative explanation of the perplexing observation by Bowman et al. of the anomalous absorption in the redshifted 21 cm line from the early Universe. In the present paper we analyzed how this neutron decay into the SFHA affects neutron stars. We showed that old neutron stars could very slowly generate the new <em>specific, described in detail</em> baryonic DM in the form of the SFHA. Some old neutron stars would release it into their tiny atmospheres, while some other old neutron stars would release it into the interstellar medium. Besides, mergers of a neutron star with another neutron star or with a black hole, accompanied by the ejection of neutron-rich material, can also lead to the formation of SFHA as the ejecta cools down. This is another interesting aspect of the multi-messenger astronomy focused on studying these mergers through the gravitational waves they generate. These mechanisms of generating new baryonic DM in the universe should have the fundamental importance. We point out the indirect observational evidence of the continuing generation of new baryonic DM. We hope that our results will stimulate a further research in this direction.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587750","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":"Curvature related geometrical properties of topologically charged EiBI-gravity spacetime","authors":"Absos Ali Shaikh ,&nbsp;Faizuddin Ahmed ,&nbsp;Mousumi Sarkar","doi":"10.1016/j.newast.2024.102272","DOIUrl":"10.1016/j.newast.2024.102272","url":null,"abstract":"<div><p>The objective of this article is to study topologically charged Eddington-inspired Born–Infeld (briefly, EiBI) gravity spacetime. It is proved that the topologically charged EiBI spacetime executes different types of pseudosymmetry, viz. Ricci generalized pseudosymmetry as <span><math><mrow><mi>R</mi><mi>⋅</mi><mi>R</mi><mo>=</mo><mi>Q</mi><mrow><mo>(</mo><mi>S</mi><mo>,</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span>, Ricci generalized projectively pseudosymmetry as <span><math><mrow><mi>P</mi><mi>⋅</mi><mi>R</mi><mo>=</mo><mfrac><mrow><mn>2</mn></mrow><mrow><mn>3</mn></mrow></mfrac><mi>Q</mi><mrow><mo>(</mo><mi>S</mi><mo>,</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span>, pseudosymmetry due to conformal curvature as <span><math><mrow><mi>C</mi><mi>⋅</mi><mi>C</mi><mo>=</mo><mo>−</mo><mfrac><mrow><mrow><mo>(</mo><msup><mrow><mi>r</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><mn>2</mn><mi>ϵ</mi><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><msup><mrow><mi>r</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></mrow></mrow><mrow><mn>6</mn><msup><mrow><mi>r</mi></mrow><mrow><mn>4</mn></mrow></msup></mrow></mfrac><mi>Q</mi><mrow><mo>(</mo><mi>g</mi><mo>,</mo><mi>C</mi><mo>)</mo></mrow></mrow></math></span> and pseudosymmetry due to conharmonic curvature as <span><math><mrow><mi>K</mi><mi>⋅</mi><mi>K</mi><mo>=</mo><mo>−</mo><mfrac><mrow><mrow><mo>(</mo><msup><mrow><mi>α</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo><mn>1</mn><mo>)</mo></mrow></mrow><mrow><mn>2</mn><msup><mrow><mi>r</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mi>Q</mi><mrow><mo>(</mo><mi>g</mi><mo>,</mo><mi>K</mi><mo>)</mo></mrow></mrow></math></span>. Also, we have exhibited the linear dependence of <span><math><mrow><mi>Q</mi><mrow><mo>(</mo><mi>g</mi><mo>,</mo><mi>C</mi><mo>)</mo></mrow></mrow></math></span> and <span><math><mrow><mi>Q</mi><mrow><mo>(</mo><mi>S</mi><mo>,</mo><mi>C</mi><mo>)</mo></mrow></mrow></math></span> on the difference <span><math><mrow><mo>(</mo><mi>C</mi><mi>⋅</mi><mi>R</mi><mo>−</mo><mi>R</mi><mi>⋅</mi><mi>C</mi><mo>)</mo></mrow></math></span>. Moreover, it is exhibited that the topologically charged EiBI spacetime is an Einstein manifold of level 3, 2-quasi Einstein, conformal 2-forms are recurrent, Ricci 1-forms are recurrent and generalized Roter type. As a special case, we have acquired the geometric structures of point-like global monopole (briefly, PGM) spacetime and topologically charged Ellis Bronnikov Wormhole (briefly, TCEBW) spacetime. Also, we have explored that the topologically charged EiBI spacetime possesses almost <span><math><mi>η</mi></math></span>-Ricci-Yamabe soliton, almost <span><math><mi>η</mi></math></span>-Ricci soliton, and for a certain condition it admits almost Ricci soliton. Further, it is also verified that such a spacetime reveals generalized curvature inheritance and for a particular condition it admits ","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587603","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":"Pulsational and eclipsing nature of TIC 140736015","authors":"B. Gürol ,&nbsp;A.-Y. Zhou","doi":"10.1016/j.newast.2024.102271","DOIUrl":"10.1016/j.newast.2024.102271","url":null,"abstract":"<div><p>We present the discovery of <span><math><mi>γ</mi></math></span> Doradus-type pulsations in the eclipsing binary TIC 140736015. We obtained the physical and geometrical parameters of this detached eclipsing binary hosting a pulsating component. Based on the Transiting Exoplanet Survey Satellite (<em>TESS</em>) observation and Gaia DR3 data of TIC 140736015, we refined the light elements of the system using <span><math><mrow><mo>(</mo><mi>O</mi><mo>−</mo><mi>C</mi><mo>)</mo></mrow></math></span> analysis and found that the eclipse times varied with a period of <span><math><mrow><mo>∼</mo><mn>2048</mn></mrow></math></span> days, probably linked to the multiperiodic pulsational nature. We showed that essentially, only secondary eclipse is seen in the phased light curve. The frequency analysis using the out-of-eclipse data reveals that all the pulsational frequencies are located in the region lower than <span><math><mrow><mn>5</mn><mspace></mspace><msup><mrow><mi>d</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>. After removing the pulsational variation from the observations we analysed the residual light curve together with the radial velocity data obtained from Gaia DR3 and find the masses and radii of the primary and secondary components as <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>429</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>022</mn></mrow></math></span> <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><mrow><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>402</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>022</mn></mrow></math></span> <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>and <span><math><mrow><msub><mrow><mi>R</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>685</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>001</mn></mrow></math></span> <span><math><msub><mrow><mi>R</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><mrow><msub><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>393</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>001</mn></mrow></math></span> <span><math><msub><mrow><mi>R</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, respectively. Regarding the location of the components on the Hertzsprung–Russell diagram both components can be a <span><math><mi>γ</mi></math></span> Dor/solar-like pulsator.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587604","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":"First photometric study of W UMa-type binary systems: BK Vul and V699 Cep","authors":"S. Adalalı ,&nbsp;E. Soydugan","doi":"10.1016/j.newast.2024.102270","DOIUrl":"https://doi.org/10.1016/j.newast.2024.102270","url":null,"abstract":"<div><p>In this study, new CCD photometric observations and photometric analysis of BK Vul and V699 Cep systems, which are classified as contact binaries in the literature, are presented. For the V699 Cep, the <em>TESS</em> light curve was also used in the photometric analysis. We determined the basic astrophysical parameters of the BK Vul and V699 Cep systems from photometric analysis using the Wilson–Devinney method. Due to the lack of spectroscopic data for both systems in the literature, these absolute parameters were approximately calculated as to be <span><math><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> = 0.73 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> = 1.39 <span><math><msub><mrow><mi>R</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> and <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> = 1.09 <span><math><msub><mrow><mi>R</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> for BK Vul, and <span><math><msub><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> = 0.36 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>1</mn></mrow></msub></math></span> = 2.40 <span><math><msub><mrow><mi>R</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> and <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> = 1.33 <span><math><msub><mrow><mi>R</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> for V699 Cep after estimating the mass of the primary component. The period decrease rate (<em>dP/dt</em>) and cyclic variation period of BK Vul were determined from the <span><math><mrow><mi>O</mi><mo>−</mo><mi>C</mi></mrow></math></span> analysis as -3.86 <span><math><mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup></mrow></math></span> day yr⁻¹ and 27 yrs., respectively. The evolutionary status of components of both systems were discussed.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541503","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":"First light simultaneous triple-channel optical observations of the OPTICAM system at the OAN-SPM","authors":"Angel Castro ,&nbsp;Raúl Michel ,&nbsp;Noel Castro Segura ,&nbsp;Diego Altamirano ,&nbsp;Carlos Tejada ,&nbsp;Joel Herrera ,&nbsp;Enrique Colorado ,&nbsp;Gerardo Sierra ,&nbsp;Liliana Altamirano-Dévora ,&nbsp;Juan Echevarría ,&nbsp;Rasjied Sloot ,&nbsp;Rudy Wijnands ,&nbsp;Iván Zavala ,&nbsp;David Rojas ,&nbsp;Juan V. Hernández Santisteban ,&nbsp;Federico Vincentelli ,&nbsp;Javier A. Hernández-Landa ,&nbsp;Song Wang ,&nbsp;Melissa Fuentes ,&nbsp;Poshak Gandhi ,&nbsp;Francisco Valenzuela","doi":"10.1016/j.newast.2024.102262","DOIUrl":"10.1016/j.newast.2024.102262","url":null,"abstract":"<div><p>OPTICAM is a triple-band optical system developed for the 2.1 m telescope of the National Astronomical Observatory in the Sierra de San Pedro Mártir (OAN-SPM). Partial engineering tests were conducted in 2019, with the complete system experiencing its first light in March 2022. The system incorporates two beam splitters, enabling simultaneous observations on three channels. Users can choose three out of the five available filters from the SDSS filter set (<span><math><mrow><msup><mrow><mi>u</mi></mrow><mrow><mo>′</mo></mrow></msup><msup><mrow><mi>g</mi></mrow><mrow><mo>′</mo></mrow></msup><msup><mrow><mi>r</mi></mrow><mrow><mo>′</mo></mrow></msup><msup><mrow><mi>i</mi></mrow><mrow><mo>′</mo></mrow></msup><msup><mrow><mi>z</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></math></span>), covering the wavelength range from 320 to 1000 nm. It offers an effective field of view of approximately 4.7, 4.7, and 5.6 arcminutes in each of its arms, respectively. Due to its design and capabilities, OPTICAM is suitable for coordinated observations with other ground-based and space-based observatories. This document presents the final instrument design and the current system status. Some of the optical tests carried out are described. We also present the results of scientific observations conducted during its first light and first year of operations.</p></div>","PeriodicalId":54727,"journal":{"name":"New Astronomy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587605","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}