Experimental Astronomy最新文献

{"title":"Deposition and performance of depth-graded W/Si multilayers on silicon pore optics for the WXPT mission","authors":"Zeying Cai,&nbsp;Zhuo Li,&nbsp;Zhengwei Li,&nbsp;Jun Xiong,&nbsp;Liqiang Qi,&nbsp;Zhongliang Li,&nbsp;Congzhan Liu,&nbsp;Lin Li,&nbsp;Shuaiwei Li,&nbsp;Shun Xia,&nbsp;Guoxiang Deng,&nbsp;Na Gao,&nbsp;Qianqing Yin,&nbsp;Haoxuan Gao,&nbsp;Xin Huang,&nbsp;Le Kang,&nbsp;Tianxiang Chen","doi":"10.1007/s10686-026-10065-9","DOIUrl":"10.1007/s10686-026-10065-9","url":null,"abstract":"<div><p>The development of high-performance depth-graded multilayer coatings is critical for next-generation hard X-ray astronomical telescopes, such as the proposed Wide-band X-ray Polarization Telescope (WXPT) mission. This work focuses on the fabrication and performance evaluation of W/Si depth-graded multilayers designed for WXPT. The coatings were deposited using a custom-built linear direct-current magnetron sputtering system. Grazing-incidence X-ray reflectometry (XRR) and cross-sectional transmission electron microscopy (TEM) revealed consistently smooth interfaces with widths of approximately 0.3-0.4 nm, demonstrating exceptional layer uniformity and minimal cumulative roughening even over hundreds of layers. Atomic force microscopy confirmed the ultra-smooth surface morphology (RMS roughness &lt; 0.3 nm) of the final coatings. The critical impact of substrate roughness on multilayer reflectivity was quantitatively demonstrated. Most importantly, hard X-ray reflectivity measurements, both from a laboratory source and synchrotron radiation, showed excellent agreement with theoretical simulations assuming an interface width of <span>(sigma )</span> = 0.4 nm. The coatings achieved high reflectivity across a broad energy band (e.g.,  25% at 20-30 keV for a design optimized for <span>(0.3^circ )</span> incidence), successfully meeting the performance targets. These results establish a robust and reliable fabrication pathway for producing high-quality W/Si multilayers, marking a significant step towards their application in Silicon Pore Optics (SPO) for the WXPT mission.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"62 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Exploring GRB localisation capability of proposed Daksha mission using coded mask imaging with its low-energy detectors","authors":"Ashish K. Mandal,&nbsp;Santosh V. Vadawale,&nbsp;Varun Bhalerao","doi":"10.1007/s10686-026-10058-8","DOIUrl":"10.1007/s10686-026-10058-8","url":null,"abstract":"<div><p><i>Daksha</i> is a proposed high-energy transient mission for the study of electromagnetic counterparts of gravitational wave sources and gamma-ray bursts. Ideally, such studies need good localization of the GRBs along with their detection itself. In its current configuration, <i>Daksha</i> can localize short-duration bursts (T<span>(_{90})</span> &lt;1s) up to the fluence &gt;1<span>(times 10^{-7}~mathrm {erg~cm^{-2}})</span> to within 5<span>(^{circ })</span>—10<span>(^{circ })</span> using projection method. However, for rapid optical follow-up observations, the localization error radius should preferably be smaller than the field of view (FOV) of most optical telescopes, which is typically &lt; 1<span>(^{circ })</span>. Thus it would be greatly advantageous if the onboard localization by <i>Daksha</i> is within 1<span>(^{circ })</span>. One possibility to improve localization capability of <i>Daksha</i> is by employing coded mask imaging technique, which is being investigated in this work. <i>Daksha</i> carries three types of detectors mounted on the hemispherical dome of the payload; low-energy (LE), medium-energy (ME) and high-energy (HE) detectors. The LE and ME detectors are placed on the outside surface of the dome, while HE detectors are housed inside. The ME detector package (MEP) with its pixellated CZT detectors is a natural choice for attempting coded mask imaging, but it may lead to loss of sensitivity (by about a factor of five) and might require additional size and weight. In this context, here we explore the feasibility of using coded aperture mask (CAM) with the LE detector package (LEP), without substantially changing the size of the overall dome structure of <i>Daksha</i>. We consider a few candidate detectors, such as 1-D position sensitive silicon drift detectors (SDDs) as well as 2-D position sensitive X-ray Charge-Coupled Devices (CCDs), reported in the recent literature. We find that it is technically feasible to conceive a coded mask telescope (CMT) using these detectors that can provide sensitivity and localization accuracy of 4<span>(times 10^{-7}~mathrm {erg~cm^{-2}})</span> and <span>(sim 0.7^{circ })</span> respectively in the best case, and 8<span>(times 10^{-7}~mathrm {erg~cm^{-2}})</span> and <span>(sim 1.8^{circ })</span> respectively in the worst case.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"62 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148261722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Observing bright pulsating white dwarfs with PLATO: A new window into the late stages of stellar evolution","authors":"Murat Uzundag,&nbsp;Alejandro H. Córsico,&nbsp;Nicholas Jannsen,&nbsp;Mukremin Kilic,&nbsp;Pierre Bergeron,&nbsp;Leandro G. Althaus,&nbsp;J. J. Hermes,&nbsp;Ingrid Pelisoli,&nbsp;Keaton J. Bell,&nbsp;Francisco C. De Gerónimo,&nbsp;Leila M. Calcaferro,&nbsp;Zsófia Bognár,&nbsp;Valérie Van Grootel,&nbsp;María E. Camisassa,&nbsp;Paulina Sowicka,&nbsp;Steven D. Kawaler,&nbsp;S. O. Kepler,&nbsp;Roberto Silvotti,&nbsp;Marcelo M. Miller Bertolami,&nbsp;Margarida Cunha","doi":"10.1007/s10686-026-10060-0","DOIUrl":"10.1007/s10686-026-10060-0","url":null,"abstract":"<div><p>We present the scientific case for exploiting the capabilities of the PLATO mission to study bright pulsating white dwarfs across a wide spectral range, including hydrogen-deficient types (GW Vir and DBV stars) and hydrogen-rich classes (classical DAVs, pulsating extremely low-mass DA white dwarfs, and ultra-massive DA white dwarfs). PLATO’s exceptional photometric precision, long-duration continuous monitoring, and extensive sky coverage promise transformative advances in white dwarf asteroseismology. Our key objectives include probing the internal structure and chemical stratification of white dwarfs, detecting secular changes in pulsation modes over extended timescales, and discovering rare or previously unknown classes of pulsators. To assess feasibility, we constructed a sample of 650 white dwarf candidates (<span>(G le 17)</span>) identified within PLATO’s Southern LOPS2 field using the PLATO complementary science catalogue combined with <i>Gaia</i> DR3, and derived atmospheric parameters through photometric modeling. This sample comprises 118 DA white dwarfs (including 23 ZZ Ceti candidates), and 41 non-DAs (including 35 DBV candidates). Simulated observations with <span>PlatoSim</span> demonstrate that PLATO will detect white dwarf pulsation modes with amplitudes as low as <span>(sim )</span>0.1 mma, depending on stellar magnitude, observation duration, pixel location, and the number of contributing cameras. We provide detailed detection limits and visibility forecasts for known pulsators across a representative range of these parameters. Furthermore, we emphasize strong synergies with <i>Gaia</i> astrometry, TESS photometry, and targeted spectroscopic campaigns, which together will enable robust mode identification and detailed stellar modeling. Collectively, these efforts will unlock unprecedented insights into white dwarf origins, evolution and internal physics, and the fate of their planetary systems.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148237294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Optical characterization of 90 GHz band TESs in a dual-polarization dual-band pixel developed for AliCPT-1","authors":"Lin Zhu,&nbsp;Jiamin Sun,&nbsp;Xufang Li,&nbsp;Ye Chai,&nbsp;Yu Xu,&nbsp;Zhouhui Liu,&nbsp;Zhengwei Li,&nbsp;He Gao,&nbsp;Mengqi Jiang,&nbsp;Qinglei Xiu,&nbsp;Daikang Yan,&nbsp;Yaqiong Li,&nbsp;Shibo Shu,&nbsp;Congzhan Liu","doi":"10.1007/s10686-026-10061-z","DOIUrl":"10.1007/s10686-026-10061-z","url":null,"abstract":"<div><p>The Ali CMB Polarization Telescope (AliCPT-1) is a ground-based telescope aiming to measure the cosmic microwave background (CMB) polarization anisotropies using transition-edge sensor (TES) bolometers. In recent years, we have been developing polarization-sensitive, dichroic TES bolometers to populate the focal plane of AliCPT-1, which is designed to accommodate 19 detector modules. This paper focuses on the optical performance of a single pixel, laying the groundwork for the future kilopixel detector array. The optical characterization includes passband, optical efficiency, and polarization response. The measured passband is 87-122 GHz, shifted upward from the target range of 77–109 GHz. This shift may be a result of an overestimation of the interlayer’s dielectric permittivity. The optical efficiency is measured to be 57%, and the cross-polarization levels are 2.3% and 6.2% for the two orthogonal 90 GHz TES bolometers. These results demonstrate the potential for scaling our single-pixel design to large-format TES arrays.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148236678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Simulation of proton-induced activation for low-Earth orbit high energy astrophysics missions","authors":"Riccardo Campana","doi":"10.1007/s10686-026-10059-7","DOIUrl":"10.1007/s10686-026-10059-7","url":null,"abstract":"<div><p>Proton-induced activation represents a major source of instrumental background for high-energy astrophysics missions in low-Earth orbit, where trapped protons, particularly during transits within the South Atlantic Anomaly region, irradiate spacecraft materials and generate radioactive isotopes. Direct Monte Carlo simulations of activation and of the ensuing decays are computationally inefficient, due to the low probability of nuclide production and the large number of decay events required for sufficient statistical accuracy. In this paper we provide a new implementation of an efficient three-step algorithm that decouples isotope production, radioactive-decay evolution, and background synthesis, enabling rapid reconstruction of activation-induced background for arbitrary irradiation histories. The method combines Geant4-based identification of all radioisotopes produced by monochromatic proton irradiations, numerical solutions of the Bateman equations for linearized decay chains, and simulation of the detector response to each isotope decay emissions. The approach greatly reduces the computational cost while maintaining accuracy, as demonstrated through validation against direct simulations, which show excellent agreement over many orders of magnitude in activity and time. This method is applied to two representative case studies: HERMES and eXTP/LAD and WFM, covering different detector technologies and orbital configurations. The presented framework enables fast exploration of design and operational scenarios (e.g., orbit selection, radiation models, or duty cycles) and is well suited for background budgeting and optimization of future high-energy space missions.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-026-10059-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148172142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Blurring Interference Seeing Motion Monitor (BLISMM): a compact instrument for simultaneous measurement of (r_0), per-frame (tau _0(n)), and (theta _0) without wind speed measurement","authors":"B. Trégon,&nbsp;G. Nicque,&nbsp;W. Benharbone,&nbsp;M. Lavaud,&nbsp;A-R. Camboulives","doi":"10.1007/s10686-026-10057-9","DOIUrl":"10.1007/s10686-026-10057-9","url":null,"abstract":"<div><p>We present the BLISMM (Blurring Interference Seeing Motion Monitor), a compact pupil-plane mask instrument measuring simultaneously the Fried parameter <span>(r_0)</span>, the per-frame coherence time <span>(tau _0(n))</span>, and the isoplanatic angle <span>(theta _0)</span> from a single video sequence on a bright star. A three-aperture mask combines a DIMM channel for <span>(r_0)</span> [21], a Fizeau interferometric channel for <span>(tau _0(n))</span>, and an aperture scintillation channel for <span>(theta _0)</span> [5]. The central contribution is a per-frame expression for <span>(tau _0(n))</span> derived directly from the contrast degradation of Fizeau fringes within individual exposures, without requiring knowledge of the atmospheric wind speed profile. Unlike the GDIMM [1], which estimates <span>(tau _0)</span> from angle-of-arrival statistics leading to an effective wind speed, or the SHIMM [18], which derives <span>(tau _0)</span> from the power spectrum of wavefront defocus over temporal sequences, the BLISMM provides an instantaneous <span>(tau _0(n))</span> at frame rate. On-sky validation at two French observatories (2014 and 2023) yields a linear correlation slope <span>(=1.00)</span> and <span>(R^2=0.98)</span> over 2033 frames between the fringe-based <span>(tau _0(n))</span> and an independent <span>(tau _0)</span> estimate. Mean values from the 2023 campaign: <span>(r_0=55)</span> mm (seeing <span>(approx 2.4'')</span> at 656 nm), <span>(tau _0(n)=1.57)</span> ms, <span>(theta _0=9.75'')</span>. The per-frame <span>(tau _0(n))</span> output enables real-time frame selection for lucky imaging without wind speed data.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148173380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Design of VDIF formatter/deformatter and network interfaces for real-time VLBI","authors":"Wei Yu","doi":"10.1007/s10686-026-10056-w","DOIUrl":"10.1007/s10686-026-10056-w","url":null,"abstract":"<div><p>In a very long baseline interferometry (VLBI) system, multiple radio telescopes far apart observe the same radio source simultaneously and then transmit the observed data from digital backends to a correlator. This paper describes a data transmission system designed for the digital backends and the hardware correlator based on field programmable gate array (FPGA), which can support real-time VLBI (e-VLBI) observations with the existing Internet. The data transmission system includes four parts: the VLBI data interchange format (VDIF) formatter, the network transmission interface, the VDIF deformatter and the network receiving interface. Where, the first two parts are embedded in the digital backends, while the latter two parts are embedded in the hardware correlator. Experimental results and real observations demonstrate that the functions of the VDIF formatter/deformatter are correct, and the throughput performance of the network transmission/receiving interfaces can meet the requirements of use.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-026-10056-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148008598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Methodological refinement of the submillimeter galaxy cross-correlation function measurements and their uncertainty estimation","authors":"Joaquín González-Nuevo,&nbsp;Laura Bonavera,&nbsp;Marcos M. Cueli,&nbsp;David Crespo,&nbsp;Jose Manuel Casas,&nbsp;Rebeca Fernández-Fernández","doi":"10.1007/s10686-026-10055-x","DOIUrl":"10.1007/s10686-026-10055-x","url":null,"abstract":"<div>\u0000 \u0000 <p>In this study, we aim to develop a new methodology to estimate the cross-correlation function and uncertainties and apply it to the analysis of magnification bias in galaxy surveys. We adopt a new methodological framework that uses a statistically rigorous approach to obtain more robust measurements for constraining cosmological parameters. This strategy involves using the full field area to count the number of different pairs for each field and combine them into a single estimation, reducing statistical uncertainty and accounting for the full information available in the data. The covariance matrix was estimated internally using an oversampled bootstrap method. We divided each field into at least five patches, that were defined automatically using a k-mean clustering algorithm. We investigate the robustness of the new methodology by comparing the results from a spectroscopic lens sample with those from a photometric lens sample, finding them to be compatible. We also analyse the cross-correlation function and auto-correlation function for individual fields in the three GAMA fields, comparing both samples. The G15 field was found to have a stronger signal compared to the other fields, suggesting that the stronger cross-correlation is produced by the rare combination of two excesses of large-scale structure in both the foreground and background samples. Our results demonstrate the robustness of the new methodology and suggest that the differences with respect to the mini-tile previously used approached may be due to physical properties of the samples themselves. The identified G15 anomalous signal warrants further investigation into its impact on cosmological parameters.</p>\u0000 </div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-026-10055-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Simulation of non X-ray background for the DIffuse X-ray Explorer (DIXE) mission","authors":"Ruixuan Tian,&nbsp;Junjie Mao,&nbsp;Jiejia Liu,&nbsp;Hai Jin,&nbsp;Wei Cui","doi":"10.1007/s10686-026-10053-z","DOIUrl":"10.1007/s10686-026-10053-z","url":null,"abstract":"<div>\u0000 \u0000 <p>DIffuse X-ray Explorer (DIXE) is a proposed high-resolution spectroscopic survey mission onboard the China Space Station. Equipped with microcalorimeters based on the Transition-edge sensor technology, it aims to survey the hot gas in the Milky Way. The performance of DIXE depends on the understanding of non X-ray background (NXB), which can strongly affect observations of diffuse X-ray emission. In this work, we simulated the NXB of DIXE in a low-earth orbit (LEO) using <span>Geant4</span>. A detailed mass model of the payload was constructed, and the major sources of NXB were identified, including cosmic rays, albedo neutrons and albedo photons. These components were implemented in <span>Geant4</span> with realistic angular and spectral distributions. We simulated the relevant physical processes of space radiation interacting with the instrument and calculated the resulting NXB. We also evaluated the delayed background from trapped protons in the South Atlantic Anomaly (SAA). Our simulations show that, at the geomagnetic equator and under solar minimum conditions, the NXB is on average <span>(4.46 times 10^{-2} ~mathrm {counts~s^{-1}~cm^{-2}~keV^{-1}})</span> in 0.1–10 keV energy band, with dominant contributions from the induced particles generated by primary cosmic protons. The NXB increases toward higher geomagnetic latitudes, reaching a maximum of <span>(1.55 times 10^{-1} ~mathrm {counts~s^{-1}~cm^{-2}~keV^{-1}})</span>. The delayed background induced by the SAA decays rapidly after exiting the anomaly and becomes negligible within approximately 5 minutes. The simulated NXB is consistent with that of similar X-ray observatories in LEOs.</p>\u0000 </div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147738888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Seeing at timau national observatory based on ERA5 dataset","authors":"Rhorom Priyatikanto,&nbsp;Clara Y. Yatini,&nbsp;Gerhana P. Putri,&nbsp;Ishfahani Rusyda,&nbsp;Evan I. Akbar,&nbsp;Agustinus G. Admiranto,&nbsp;Ferdhiansyah Noor,&nbsp;Siti Maryam,&nbsp;Elyyani Elyyani,&nbsp;Abd Rachman","doi":"10.1007/s10686-026-10054-y","DOIUrl":"10.1007/s10686-026-10054-y","url":null,"abstract":"<div>\u0000 \u0000 <p>Understanding the seeing conditions is crucial for astronomical observations using a ground-based telescope. This study analyzes long-term atmospheric data (2002–2021) from the ERA5 dataset to assess the seeing conditions at the new Timau National Observatory in Indonesia, which hosts a 3.8-meter optical telescope. While the ERA5 dataset shows remarkable agreement with radiosonde data for temperature and wind speed, it tends to underestimate seeing at Eltari Airport, Kupang. Despite this discrepancy, the ERA5 data suggest a median seeing of <span>(varvec{0.79})</span> arcseconds at Timau, with optimal seeing conditions in March and November and greater variability during the May to September dry season. These findings are crucial for the planning and operation of the observatory, which requires excellent seeing conditions for its three-band optical imager and a near-infrared camera. Although the seeing at Timau is not as good as at some other observatories, the conditions at Timau make it an observatory that has good prospects for equatorial regions.</p>\u0000 </div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"61 3","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147738053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}