Astronomische Nachrichten最新文献

{"title":"What is the unknown “star” or “∼star” recorded in Korean historical books?","authors":"Jaegeun Park,&nbsp;Junhyeok Jeon,&nbsp;Hongjun An","doi":"10.1002/asna.20240068","DOIUrl":"10.1002/asna.20240068","url":null,"abstract":"<p>This study discusses historical records of Korea that mention “stars” possibly related to astronomical transient events. We selected 19 such records and scrutinized them by cross-checking with records of other countries to identify those events. Ten events were identified as comets based on their described motions and tails. We further confirmed this by comparing them with records from other countries. Five events were classified as meteors based on descriptions of their movements, sizes, and shapes. We speculate that two recordings about “big stars” (大星) are typographical errors for “Mars” (火星), as the descriptions of these big stars seem to be consistent with the properties of the latter. This leaves two unidentified events, and we search lists of astronomical transients for their counterparts. Our work emphasizes the uncertainties and challenges caused by the limited information in the historical records while exploring the usefulness of historical records to enhance the understanding of astrophysical transient events.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 8","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946843","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":"Toward an efficient second-order method for computing the surface gravitational potential on spherical-polar meshes","authors":"Oliver Gressel,&nbsp;Udo Ziegler","doi":"10.1002/asna.20240056","DOIUrl":"10.1002/asna.20240056","url":null,"abstract":"<p>Astrophysical accretion discs that carry a significant mass compared with their central object are subject to the effect of self-gravity. In the context of circumstellar discs, this can, for instance, cause fragmentation of the disc gas, and—under suitable conditions—lead to the direct formation of gas-giant planets. If one wants to study these phenomena, the disc's gravitational potential needs to be obtained by solving the Poisson equation. This requires to specify suitable boundary conditions. In the case of a spherical-polar computational mesh, a standard multipole expansion for obtaining boundary values is not practicable. We hence compare two alternative methods for overcoming this limitation. The first method is based on a known Green's function expansion (termed “CCGF”) of the potential, while the second (termed “James' method”) uses a surface screening mass approach with a suitable discrete Green's function. We demonstrate second-order convergence for both methods and test the weak scaling behavior when using thousands of computational cores. Overall, James' method is found superior owing to its favorable algorithmic complexity of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mi>O</mi>\u0000 <mfenced>\u0000 <msup>\u0000 <mi>n</mi>\u0000 <mn>3</mn>\u0000 </msup>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation>$$ sim mathcal{O}left({n}^3right) $$</annotation>\u0000 </semantics></math> compared with the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 <mi>O</mi>\u0000 <mfenced>\u0000 <msup>\u0000 <mi>n</mi>\u0000 <mn>4</mn>\u0000 </msup>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation>$$ sim mathcal{O}left({n}^4right) $$</annotation>\u0000 </semantics></math> scaling of the CCGF method.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 8","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20240056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946842","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":"Does the Nebra Sky Disk encode an early Bronze Age report of a galactic supernova?","authors":"Nikolaus Vogt,&nbsp;Juan Crocco","doi":"10.1002/asna.20240042","DOIUrl":"10.1002/asna.20240042","url":null,"abstract":"<p>The Nebra Disk is one of the earliest astronomical manifestations of humanity in Central Europe. We interpret the striking sevenfold stellar group shown on the disk as a celestial conjunction of the five naked-eye visible planets together with Pollux and Castor in the constellation Gemini (happening in 2210BC) and the dominating large, filled circle as a bright supernova, probably corresponding to the remnant 3C58 in Cassiopeia. We believe that a close coincidence of these two extremely rare celestial events, that does never happen more than once in a human lifetime, could have impressed people of that epoch in a way that it was conveyed orally over several generations, until some Bronze Age artist created the Nebra Disk. If this interpretation is correct, it could offer a rather exact dating of a supernova explosion observed about 4200 years ago, more precise than any other dating methods for past supernova events, possibly leading to significant new insights into the underlying physics of supernovae.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 8","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885441","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":"Solar disk integration polarimeter: An automated disk-integration full-Stokes-vector solar feed for the Potsdam Echelle Polarimetric and Spectroscopic Instrument spectrograph","authors":"Klaus G. Strassmeier,&nbsp;Ilya Ilyin,&nbsp;Manfred Woche,&nbsp;Frank Dionies,&nbsp;Michael Weber,&nbsp;Arto Järvinen,&nbsp;Carsten Denker,&nbsp;Ekaterina Dineva,&nbsp;Meetu Verma,&nbsp;Thomas Granzer,&nbsp;Wilbert Bittner,&nbsp;Svend-Marian Bauer,&nbsp;Jens Paschke,&nbsp;Hakan Önel","doi":"10.1002/asna.20240033","DOIUrl":"10.1002/asna.20240033","url":null,"abstract":"<p>We introduce a new solar feed for the PEPSI nighttime spectrograph of the LBT. It enables spectroscopy of the Sun-as-a-star in circular polarization (CP) and linear polarization (LP) with a spectral resolution of 250,000 (≈0.025Å or <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>600</mn>\u0000 <mspace></mspace>\u0000 <mi>m</mi>\u0000 <mspace></mspace>\u0000 <msup>\u0000 <mi>s</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ 600kern0.1em mathrm{m}kern0.1em {mathrm{s}}^{-1} $$</annotation>\u0000 </semantics></math>) for the wavelength range 383–907 nm. The polarimeter is a dual-beam design with a modified Wollaston prism as beam splitter and linear polarizer combined with a retractable super-achromatic <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>λ</mi>\u0000 <mo>/</mo>\u0000 <mn>4</mn>\u0000 </mrow>\u0000 <annotation>$$ lambda /4 $$</annotation>\u0000 </semantics></math> retarder. The Wollaston beam diameter is 14 mm and large enough that it does not require a classical telescopic feed anymore. Both polarimetric beams are re-imaged into respective integration spheres from which two fibers feed the scrambled light to the spectrograph. The system is fully automated in the sense that it finds the Sun in the morning, closes the guider loop, observes a predefined number of individual spectra, and moves to a home position at the end of the day. Among the scientific aims is Zeeman–Doppler imaging of the Sun as a star over the next activity cycle. Our first-light application detects a clear Stokes-V/I profile with a full amplitude of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mn>10</mn>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>4</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ 1times {10}^{-4} $$</annotation>\u0000 </semantics></math> on, for example, October 13, 2023, suggesting a solar disk-averaged line-of-sight net magnetic field of +0.37±0.02 G. Comparison of this value with a contemporary full-disk line-of-sight magnetogram suggests an unsigned mean field of about ≈13 G.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/asna.20240033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742147","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":"Evaluating a sigmoid dark energy model to explain the Hubble tension","authors":"Sergio Torres-Arzayus,&nbsp;Camilo Delgado-Correal,&nbsp;Mario-Armando Higuera-G,&nbsp;Sebastián Rueda-Blanco","doi":"10.1002/asna.20240034","DOIUrl":"10.1002/asna.20240034","url":null,"abstract":"&lt;p&gt;In this study, we analyze Type Ia supernovae (SNe Ia) data sourced from the Pantheon+ compilation to investigate late-time physics effects influencing the expansion history, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ H(z) $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, at redshifts &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ left(z&lt;2right) $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Our focus centers on a time-varying dark energy (DE) model that introduces a rapid transition in the equation of state, at a specific redshift, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mi&gt;a&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {z}_a $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, from the baseline, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;w&lt;/mi&gt;\u0000 &lt;mi&gt;Λ&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {w}_{Lambda}=-1 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, value to the present value, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;w&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {w}_0 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. The change in the equation of state is implemented as a transition in the DE density scale factor driven by a sigmoid function. The constraints obtained for the DE sigmoid phenomenological parametrization have broad applicability for dynamic DE models that invoke late-time physics. Our analysis indicates that the sigmoid model provides a slightly better, though not statistically significant, fit to the SNe Pantheon+ data compared to the standard &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Λ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ Lambda $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; cold dark matter (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;ΛCDM&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ Lambda mathrm{CDM}","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720915","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":"Size of the accretion disc in the recurrent nova T CrB","authors":"R. K. Zamanov,&nbsp;K. A. Stoyanov,&nbsp;V. Marchev,&nbsp;M. Minev,&nbsp;D. Marchev,&nbsp;M. Moyseev,&nbsp;J. Martí,&nbsp;M. F. Bode,&nbsp;R. Konstantinova-Antova,&nbsp;S. Stefanov","doi":"10.1002/asna.20240036","DOIUrl":"10.1002/asna.20240036","url":null,"abstract":"&lt;p&gt;We present high-resolution (0.06 Å px&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt; &lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {}^{-1} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) spectroscopic observations of the recurrent nova T Coronae Borealis obtained during the last 1.5 years (September 2022–January 2024), with the 2.0-m RCC telescope of the Rozhen National Astronomical Observatory, Bulgaria. Double-peaked emission is visible in the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {H}_{alpha } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; line after the end of the superactive state. We subtract the red giant contribution and measure the distance between the peaks (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;v&lt;/mi&gt;\u0000 &lt;mi&gt;a&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ Delta {v}_a $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) of the line. For the period July 2023–January 2024, we find that &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;v&lt;/mi&gt;\u0000 &lt;mi&gt;a&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ Delta {v}_a $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is in range &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;90&lt;/mn&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mi&gt;Δ&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;v&lt;/mi&gt;\u0000 &lt;mi&gt;a&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mn&gt;120&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ 90&lt;Delta {v}_a&lt;120 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; km s&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt; &lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {}^{-1} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Assuming that the emission is from the accretion disc around the white dwarf, we find average radius of the accretion disc &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 ","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720914","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":"Spectroscopic and dynamic orbital analyses of metal-poor and high proper-motion stars: I. HD 8724 and HD 195633","authors":"M. Marışmak,&nbsp;T. Şahin,&nbsp;F. Güney,&nbsp;O. Plevne,&nbsp;S. Bilir","doi":"10.1002/asna.20240047","DOIUrl":"10.1002/asna.20240047","url":null,"abstract":"<p>In this study, spectral, age, kinematic, and orbital dynamical analyses were conducted on metal-poor and high proper-motion (HPM) stars, HD 8724 and HD 195633, selected from the Solar neighborhood. This analysis combines detailed abundance measurements, kinematics, and orbital dynamics to determine their origin. Standard 1D local thermodynamic equilibrium analysis provides a fresh determination of the atmospheric parameters: <i>T</i>_{eff =} 4700 ± 115 K, log <i>g</i> = 1.65 ± 0.32 cgs, [Fe/H] = −1.59 ± 0.04 dex, and a microturbulent velocity <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ξ</mi>\u0000 <mo>=</mo>\u0000 </mrow>\u0000 <annotation>$$ xi = $$</annotation>\u0000 </semantics></math> 1.58 ± 0.50 km s⁻¹ for HD 8724 and <i>T</i>_eff = 6100 ± 205 K, log <i>g</i> = 3.95 ± 0.35 cgs, [Fe/H] = −0.52 ± 0.05 dex, and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ξ</mi>\u0000 <mo>=</mo>\u0000 </mrow>\u0000 <annotation>$$ xi = $$</annotation>\u0000 </semantics></math>1.26 ± 0.50 km s⁻¹ for HD 195633. The ages were estimated using a Bayesian approach (12.25 Gyr for HD 8724 and 8.15 Gyr for HD 195633). The escape scenarios of these stars from 170 candidate globular clusters (GCs) in the Galaxy were also investigated because of their chemical and physical differences (HPM and metal-poor nature). Accordingly, the calculated probability of encounter (59%) for HD 8724 at a distance of five tidal radius suggests that star HD 8724 may have escaped from NGC 5139 (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>ω</mi>\u0000 </mrow>\u0000 <annotation>$$ omega $$</annotation>\u0000 </semantics></math> Cen), supported by its highly flattened orbit and may belong to a subpopulation of this GC. Conversely, HD 195633's kinematics, age, and metal abundances point toward an escape from the bulge GC NGC 6356.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613004","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":"The Mira discovery problem—Observations by David Fabricius in 1596 and 1609 (and by others before?): Positional accuracy, brightness, color index, and period","authors":"R. Neuhäuser,&nbsp;D. L. Neuhäuser,&nbsp;M. Mugrauer,&nbsp;D. Luge,&nbsp;J. Chapman","doi":"10.1002/asna.20230131","DOIUrl":"10.1002/asna.20230131","url":null,"abstract":"<p>The pulsating variable star Mira (<i>o</i> Ceti) was observed by David Fabricius (Frisia) in 1596 and 1609. We review suggested previous detections (e.g., China, Hipparchos). We analyze all Mira records from Fabricius in their historical context. Fabricius measured the separation of Mira to other stars to ±1.6−1.7′. From his texts, we derive a brightness (slightly brighter than Hamal) of ca. 1.9±0.1 mag and a color index B-V<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>≃</mo>\u0000 </mrow>\u0000 <annotation>$$ simeq $$</annotation>\u0000 </semantics></math>1.3−1.4 mag (‘like Mars’) for 1596 Aug 3 (Jul.). Mira started to fainten 19 days later and was observed until mid/late Oct. We show why such a red star cannot be followed by the naked eye until ca. 6 mag: For Mira's color at disappearance and altitude from Frisia, the limit is reduced by ca. 1.0 mag. Since Fabricius connected the Mira brightening with the close-by prograde Jupiter, he re-detected it only 12 years later, probably shortly before a relatively bright maximum—discoveries are strongly affected by biases. A Mira period of 330.2 days is consistent with both the oldest data (from Fabricius 1596 to Hevelius 1660) and the most current data (VSX 2004–2023), so that we see no evidence for secular period or phase shifts. (We also present Fabricius' observations of P Cygni in 1602.)</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141547641","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":"Updated absolute parameters and kinematics of IS CMa","authors":"Serkan Evcil,&nbsp;Simge Adalalı,&nbsp;Neslihan Alan,&nbsp;Remziye Canbay,&nbsp;Selcuk Bilir","doi":"10.1002/asna.20240038","DOIUrl":"10.1002/asna.20240038","url":null,"abstract":"&lt;p&gt;Eclipsing binary systems are significant objects for astrophysics in that direct observations can determine the fundamental parameters of stars. In this study, we precisely determined the fundamental parameters of the binary component stars obtained by simultaneous analysis of radial velocities and the TESS light curve using the Wilson and Devinney code. Following the analysis, the masses and radii of the primary and secondary components were determined as &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;1.58&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;0.01&lt;/mn&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mo&gt;⊙&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {M}_1=1.58pm 0.01{M}_{odot } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.48&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;0.02&lt;/mn&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mo&gt;⊙&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {M}_2=0.48pm 0.02{M}_{odot } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;1.93&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;0.01&lt;/mn&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mo&gt;⊙&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}_1=1.93pm 0.01{R}_{odot } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;1.14&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;0.01&lt;/mn&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mo&gt;⊙&lt;/mo&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}_2=1.14pm 0.01{R}_{odot } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, respectively. Furthermore, the distance of IS CMa is calculated as &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;92.7&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;6.5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ 92.7pm 6.5 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503613","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":"Unraveling the link between Type II supernova luminosity and host galaxy velocity dispersion","authors":"A. Hernández Flores,&nbsp;F. Olivares E.,&nbsp;L. Morelli,&nbsp;P. Wiseman,&nbsp;C. P. Gutierrez","doi":"10.1002/asna.20230146","DOIUrl":"https://doi.org/10.1002/asna.20230146","url":null,"abstract":"<p>Type II supernovae (SNe II) have emerged as valuable cosmological probes, serving as alternative and independent tools to Type Ia supernova (SN Ia) cosmology. However, the Hubble diagram dispersion for SNe II is significantly larger than for SNe Ia. In this study, we investigate the SN II luminosity and the host galaxy velocity dispersion with the purpose of improving the scatter in the SN II Hubble diagram. We selected a sample of SNe II discovered by the Dark Energy Survey (DES), and we measured the spectra of their host galaxies using the VLT/FORS2 and Magellan-Baade/MagE spectrographs. From those galaxy spectra, we calculated the stellar velocity dispersion in the central region. Using the effective Sérsic radius from the DES imaging, we standardized the velocity dispersion values to a common aperture. From their <i>i</i>-band light curves, we determined a characteristic plateau brightness for our SNe. For this purpose, we developed an algorithm designed to parameterize the plateau phase. After computing the SN absolute magnitudes using the standard cosmology, we found a modest correlation with the host galaxy velocity dispersion (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>R</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 <mo>=</mo>\u0000 <mn>0.57</mn>\u0000 </mrow>\u0000 <annotation>$$ {R}^2=0.57 $$</annotation>\u0000 </semantics></math>). These findings could significantly contribute to SN II cosmology, paving the way for SNe II as more robust cosmological probes.</p>","PeriodicalId":55442,"journal":{"name":"Astronomische Nachrichten","volume":"345 6-7","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142021769","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}