Photometric Analysis Research Articles

Enhancing Amperometric Ozone Gas Sensing with Room-Temperature Ionic Liquids and Platinum-Based Electrodes.

Ozone (O3) poses serious health risks, prompting numerous countries to implement regulations that establish exposure limits and emission controls, for example, the air quality index (AQI) for O3 ranging from 50 to 150 parts per billion (ppb), with natural levels at around 30 ppb. Electrochemical sensors are favored for detecting pollutant gases due to their high sensitivity, low cost, portability, energy efficiency, and capability for selective detection. In this study, we developed an O3 sensor employing carbon-supported Pt-based binary and ternary nanorods (NRs) combined with room-temperature ionic liquids (RTILs) as electrolytes, aiming at highly sensitive and selective detection of O3 at ppb levels. Initial screening of the O3 sensing performance across different electrolytes identified H2SO4 and [C4mpyrr][NTf2] (BMP) as the most sensitive options. BMP outperformed H2SO4 in terms of linearity, selectivity, reproducibility, and response/recovery times, despite a relatively lower sensitivity. Electrochemical testing of Pt, PtAu, PtAg, and PtAuAg NR electrodes in BMP revealed that the addition of Au enhanced the linear response, while Ag improved sensitivity. Consequently, the ternary PtAuAg NR electrode exhibited the highest sensitivity (10.5 nA/ppm (parts per million)) and a broad detection range, fulfilling the AQI requirements for O3. The current response from the PtAuAg NR electrode closely aligned with results from an ultraviolet (UV) photometric analyzer, confirming its accuracy. Notably, this electrode contains only 20 wt % noble metals, which reduces the overall cost to just 11% of that of a traditional pure Au electrode.

Evaluating cosmological biases using photometric redshifts for Type Ia Supernova cosmology with the Dark Energy Survey Supernova Program

Abstract Cosmological analyses with Type Ia Supernovae (SNe Ia) have traditionally been reliant on spectroscopy for both classifying the type of supernova and obtaining reliable redshifts to measure the distance-redshift relation. While obtaining a host-galaxy spectroscopic redshift for most SNe is feasible for small-area transient surveys, it will be too resource intensive for upcoming large-area surveys such as the Vera Rubin Observatory Legacy Survey of Space and Time, which will observe on the order of millions of SNe. Here we use data from the Dark Energy Survey (DES) to address this problem with photometric redshifts (photo-z) inferred directly from the SN light-curve in combination with Gaussian and full p(z) priors from host-galaxy photo-z estimates. Using the DES 5-year photometrically-classified SN sample, we consider several photo-z algorithms as host-galaxy photo-z priors, including the Self-Organizing Map redshifts (SOMPZ), Bayesian Photometric Redshifts (BPZ), and Directional-Neighbourhood Fitting (DNF) redshift estimates employed in the DES 3x2 point analyses. With detailed catalog-level simulations of the DES 5-year sample, we find that the simulated w can be recovered within ±0.02 when using SN+SOMPZ or DNF prior photo-z, smaller than the average statistical uncertainty for these samples of 0.03. With data, we obtain biases in w consistent with simulations within ∼1σ for three of the five photo-z variants. We further evaluate how photo-z systematics interplay with photometric classification and find classification introduces a subdominant systematic component. This work lays the foundation for next-generation fully photometric SNe Ia cosmological analyses.

Altered cervical proprioception and biomechanics in obstructive sleep apnea: a case-control study.

This study aimed to compare cervical proprioception and related biomechanical factors among patients with Obstructive Sleep Apnea (OSA) and asymptomatic controls. In this case-control study, polysomnography scores (apnea-hypopnea index-AHI) were examined to determine the disease severity of the OSA group. Also, we evaluated cervical proprioception by using a laser pointer to detect joint repositioning error sense in cervical rotational movements. Comparison statistics were also conducted for the cervical musculoskeletal variables such as range of motion (ROM) with bubble inclinometer, cranio-cervical (CVA), and thoracic posture (TKA) through photometric analysis, neck flexor muscle endurance test, and pain pressure thresholds of trapezius (PPT). This case-control study included 59 male participants: patients with OSA (n = 29; mean age = 49.10 years; mean BMI = 28.41kg/m2) and asymptomatic controls (n = 30; mean age = 49.73 years; mean BMI = 26.89 ± 3.60kg/m2). The mean AHI score was 26.06 events/hour, categorizing the severity of OSA as mild (31.03%), moderate (31.03%), and severe (37.94%). Patients with OSA demonstrated significantly poorer cervical proprioception compared to controls for both sides of cervical rotation with larger effect sizes (d:1.36-1.45; p < 0.05). Also, cervical ROM, CVA, TKA, neck flexor muscle endurance test, and PPT values were altered in the OSA group compared to the control group (p < 0.05). Impaired cervical proprioception may be a previously unrecognized factor associated with OSA. This finding has implications for understanding the mechanisms underlying cervical musculoskeletal changes in OSA and for developing potential new interventions or exercise designs targeting postural control.

Spectroscopic and Photometric Confirmation of 3 Globular and 14 Intermediate-age Clusters in the Irr II Galaxy NGC 3077

We present the results from spectroscopic and photometric analysis of 17 globular cluster (GC) candidates in the Irr II galaxy NGC 3077. The GC candidates were selected on the Hubble Space Telescope images and were cleaned of foreground Galatic stars using the GAIA parameters. We carried out aperture photometry using the multiband archival images from the Sloan Digital Sky Survey, Two Micron All Sky Survey of all candidates, and low resolution (R = 1000) spectroscopic observations of 12 GC candidates and three suspected foreground stars using the Optical System for Imaging and Low-Intermediate-Resolution Integrated Spectroscopy/Multi-Object Spectra mode at the Gran Telescopio Canarias. Age, metallicity, and extinction values were determined using both spectroscopic and photometric data, independently. We find three of the 17 candidates are old (age > 10 Gyr), metal-poor ([Fe/H] < −1.0 dex), and massive (mass > 105 M ⊙) GCs with characteristics similar to the classical GCs in the Milky Way. The rest are intermediate-age clusters (IACs) with typical ages of 3–4 Gyr and in general metal-rich clusters. The radial velocities of both populations are within 100 km s−1 of the recessional velocity of the host galaxy. A relatively large population of IACs and low value of GC specific frequency (S N = 0.7) suggest that the preinteraction galaxy was actively forming stars and star clusters, and is unlikely to be a dwarf elliptical as suggested in some previous works.

The role of thermal instability in accretion outbursts in high-mass stars

High-mass young stellar objects (HMYSOs) can exhibit episodic bursts of accretion, accompanied by intense outflows and luminosity variations. Understanding the underlying mechanisms driving these phenomena is crucial for elucidating the early evolution of massive stars and their feedback on star formation processes. Thermal instability (TI) due to hydrogen ionisation is among the most promising mechanisms of episodic accretion in low-mass ($M_* protostars. Its role in HMYSOs has not yet been determined. Here we investigate the properties of TI outbursts in young massive ($M_* 5$ msun ) stars, and compare them to those that have been observed to date. We employed a 1D numerical model to simulate TI outbursts in HMYSO accretion discs. We varied the key model parameters, such as stellar mass, mass accretion rate onto the disc, and disc viscosity, to assess the TI outburst properties. Our simulations show that modelled TI bursts can replicate the durations and peak accretion rates of long outbursts (a few years to decades) observed in HMYSOs with similar mass characteristics. However, they struggle with short-duration bursts (less than a year) with short rise times (a few weeks or months), suggesting the need for alternative mechanisms. Moreover, while our models match the durations of longer bursts, they fail to reproduce the multiple outbursts seen in some HMYSOs, regardless of model parameters. We also emphasise the significance of not just evaluating model accretion rates and durations, but also performing photometric analysis to thoroughly evaluate the consistency between model predictions and observational data. Our findings suggest that some other plausible mechanisms, such as gravitational instabilities and disc fragmentation, can be responsible for generating the observed outburst phenomena in HMYSOs, and we underscore the need for further investigation into alternative mechanisms driving short outbursts. However, the physics of TI is crucial in sculpting the inner disc physics in the early bright epoch of massive star formation, and comprehensive parameter space exploration; the use of 2D modelling is essential to obtaining a more detailed understanding of the underlying physical processes. By bridging theoretical predictions with observational constraints, this study contributes to advancing our knowledge of HMYSO accretion physics and the early evolution of massive stars.

Photometric and Spectroscopic Analysis of Eight Totally Eclipsing Contact Binaries with Small Mass Ratios

This paper selected eight totally eclipsing contact binaries for photometric and spectroscopic studies. Spectral data were analyzed by University of Lyon Spectroscopic analysis Software, and photometric data were analyzed using PHOEBE through Markov Chain Monte Carlo (MCMC) sampling. We used two methods to calculate the initial values for running MCMC: one method is a new approach proposed by ourselves to model light curves without spots, while the other method is the genetic algorithm, which can determine physical parameters with spots. The results imply that these eight targets are all contact binary stars with a small mass ratio below 0.25. There are four systems exhibiting the O’Connell effect. By adding a dark spot on the primary component, the ideal fitting can be obtained. Meanwhile, it was found that two systems are shallow contact binaries, while the remaining six are moderate contact binaries. An O − C analysis of the eight eclipsing binary stars revealed that seven of them exhibit long-term changes. Four of them display a long-term decreasing trend in orbital period, while the other three show a long-term increasing trend, and two targets exhibit periodic variations. A decrease in period may be caused by the transfer of matter from the more massive component to the less massive component, while an increase in period may be caused by transfer in the opposite way. The absolute physical parameters, orbital angular momentum, initial masses, and ages of these eight systems were calculated. Additionally, their mass–luminosity and mass–radius distributions were analyzed.

Characterization of the Blue Straggler Star Populations, through Statistical, Photometric, and Spectral Energy Distribution Analysis, in the Old Open Cluster: NGC 2243

We present a statistical, photometric, and spectral energy distribution (SED) analysis of the poorly studied old open cluster: NGC 2243, to characterize its blue straggler star (BSS) population. We applied ensemble-based unsupervised machine learning methods to estimate the membership probabilities using Gaia Data Release 3 (DR3) astrometric data. NGC 2243 is an open cluster that is 3.67 Gyr old with a metallicity of −0.375 dex, situated at a distance of 3.65 kpc. By analyzing the position of cluster members on the color–magnitude diagram using MIST isochrones, we have identified 12 potential BSSs in NGC 2243. We fitted the radial surface density profile and investigated the dynamical state and mass segregation effect of the cluster. It is found that the BSSs are significantly concentrated within the central region. We used data from Swift/UVOT, Gaia DR3, Pan-STARRS1 DR2, 2MASS, and WISE to fit the SEDs of the 12 identified BSSs using VOSA. We estimated the masses of the BSSs from the Hertzsprung–Russell diagram and found that they ranged from 1.25 to 2.22 M ☉. Consequently, we concluded that the BSSs likely gained 0.11–1.08 M ☉ through the mass transfer or merger channels. We discovered a hot companion associated with one BSS candidate, which has a temperature of 19,000 K, a luminosity of 0.55 L ☉, and a radius of 0.065 R ☉. The hot companion is probably a white dwarf, with its mass estimated to be approximately 0.18–0.20 M ☉ and an age of 186 Myr, suggesting it is a post-mass-transfer (Case A or Case B) system.

Changes in facial soft tissue support with and without a maxillary labial flange.

To quantify facial esthetic outcomes of prosthetic upper lip support in both full animation and repose for patients with an existing implant-supported fixed complete dental prosthesis (ISFCDP). Twenty patients had a removable prosthetic labial flange fabricated for their existing maxillary prosthesis. The 3dMDface system was used to capture video sets of each patient going from repose to high smile with and without the labial flange. A single frame representing high smile and repose was selected from each video. Five facial anatomic markers and 21 individual points on the upper lip were evaluated for both image sets using quantitative photometric analysis. To provide a qualitative assessment, the same images were shown to dentists, laypeople, and the research subjects (patients) to determine which they found to be more esthetically pleasing, or if there was no difference. Quantitative data was evaluated using paired t-tests. The two-dimensional analysis showed a difference with and without a labial flange for lip projection and lip thickness. Additionally, 13 out of 21 landmarks in the three-dimensional analysis showed differences when comparing the superimposed labial flange and no flange linear difference values between high smile and repose. Survey results showed that research subjects (54.41%), dentists (51.50%), and laypeople (44.50%), all preferred labial flange versus no flange photos or were not able to tell a difference. Qualitative and quantitative results suggest that a prosthetic labial flange has an impact on upper lip support. Clinicians should consider lip support both in full animation and repose when treatment planning for the maxillary ISFCDP.

Photometric Analysis for Trichlorophenoxyacetic Acid in Water and Bottom Sediments with the Use of Extraction

Photometric Analysis for Trichlorophenoxyacetic Acid in Water and Bottom Sediments with the Use of Extraction

KISS: Instrument Description and Performance

Kinetic inductance detectors (KIDs) have been proven as reliable systems for astrophysical observations, especially in the millimeter range. Their compact size enables them to optimally fill the focal plane, thus boosting sensitivity. The KIDs Interferometric Spectral Surveyor (KISS) instrument is a millimeter camera that consists of two KID arrays of 316 pixels each coupled to a Martin–Puplett interferometer (MPI). The addition of the MPI grants the KID camera the ability to provide spectral information in the 100 and 300 GHz range. In this paper, we report the main properties of the KISS instrument and its observations. We also describe the calibration and data analysis procedures used. We present a complete model of the observed data including the sky signal and several identified systematics. We have developed a full photometric and spectroscopic data analysis pipeline that translates our observations into science-ready products. We show examples of the results of this pipeline on selected sources: the Moon, Jupiter, and Venus. We note the presence of a deficit of response with respect to expectations and laboratory measurements. The detector's noise level is consistent with values obtained during laboratory measurements, pointing to a suboptimal coupling between the instrument and the telescope as the most probable origin for the problem. This deficit is large enough to prevent the detection of galaxy clusters, which were KISS's main scientific objective. Nevertheless, we have demonstrated the feasibility of this kind of instrument in the prospect of other KID interferometers (such as the CONCERTO instrument). In this regard, we have developed key instrumental technologies such as optical conception, readout electronics, and raw calibration procedures, as well as adapted data analysis procedures.

A Tale of NGC 3785: The formation of an ultra-diffuse galaxy at the end of the longest tidal tail

Aims. We present the discovery of an extended and faint tail observed in the isolated environment associated with galaxy NGC 3785. This study additionally provides observational evidence supporting the formation of ultra-diffuse galaxies (UDGs) at the end of the tail. Methods. We utilized the Gnuastro software to detect and analyze the low surface brightness structures in the optical g- and r-bands using data from the Dark Energy Camera Legacy Survey. We created a detection map to identify the faint tail and measured its length using cubic spline fitting. Additionally, we found 84 star-forming clumps along the tail and performed photometric analysis on the tail portion after applying a significance threshold on the signal-to-noise ratio. Results. We have measured the projected length of the tail, which is ∼390 kpc. We propose that this tail arises from the interaction of the NGC 3785 with a gas-rich galaxy, which ends up as a UDG at the end of the tail.

Lossy Compression of Integer Astronomical Images Preserving Photometric Properties* *This work was supported in part by the Spanish Ministry of Science and Innovation (MICINN) and by the European Regional Development Fund (FEDER), funded by MCIN/AEI/10.13039/501100011033/FEDER, UE, under grant PID2021-125258OB-I00; also by the Catalan Government under grant SGR2021-00643; and also by the “PhotSat” project under the Institute for Space Studies of

Observatories are producing astronomical image data at quickly increasing rates. As a result, the efficiency of the compression methods employed is critical to meet the storage and distribution requirements of both observatories and scientists. This paper presents a novel lossy compression technique that is able to preserve the results of photometry analysis with high fidelity while improving upon the state of the art in terms of compression performance. The proposed compression pipeline combines a flexible bi-region quantization scheme with the lossless, dictionary-based, LPAQ9M encoder. The quantization process allows compression performance and photometric fidelity to be precisely tailored to different scientific requirements. A representative data set of 16-bit integer astronomical images produced by telescopes from all around the world has been employed to empirically assess its compression-fidelity trade-offs, and compare them to those of the de facto standard Fpack compressor. In these experiments, the widespread SExtractor software is employed as the ground truth for photometric analysis. Results indicate that after lossy compression with our proposed method, the decompressed data allows consistent detection of over 99% of all astronomical objects for all tested telescopes, maintaining the highest photometric fidelity (as compared to state of the art lossy techniques). When compared to the best configuration of Fpack (Hcompress lossy using 1 quantization parameter) at similar compression rates, our proposed method provides better photometry precision: 7.15% more objects are detected with magnitude errors below 0.01, and 9.13% more objects with magnitudes below SExtractor’s estimated measurement error. Compared to the best lossless compression results, the proposed pipeline allows us to reduce the compressed data set volume by up to 38.75% and 27.94% while maintaining 90% and 95%, respectively, of the detected objects with magnitude differences lower than 0.01 mag; and up to 18.93% while maintaining 90% of the detected objects with magnitude differences lower than the photometric measure error.

A comprehensive study of five candidate δ Scuti-type pulsators in detached eclipsing binaries

Context. Pulsating stars in eclipsing binaries (EBs) provide an excellent opportunity to obtain precise, model-independent stellar parameters for studying these oscillations in detail. One of the most common classes of pulsators found in such EBs exhibits δ Scuti-type oscillations. Characterising these pulsators using the precise stellar parameters obtained using EB modelling can help us better understand such stars, and provide strong anchors for asteroseismic studies. Aims. We performed a comprehensive photometric and spectroscopic analysis of candidate pulsators in detached EBs, to add to the sample of such systems with accurately determined absolute parameters. Methods. We performed radial velocity and light curve modelling to estimate the absolute stellar parameters, and detailed spectroscopic modelling to obtain the global metallicity and temperatures. Frequency power spectra were obtained using residuals from binary modelling. Finally, we used isochrones to determine the age of the stars, and compared the estimated physical parameters to the theoretically obtained values. Results. We present a detailed analysis of four candidate δ Scuti-type pulsators in EBs, and update the light curve analysis of the previously studied system TIC 308953703. The masses and radii of components are constrained to a high accuracy, which helps us constrain the age of the systems. We perform a Fourier analysis of the observed oscillations, and try to explain their origin. For TIC 81702112, we report tidal effects causing amplitude variation in the oscillation frequencies over the orbital phase.

GRANDMA Observations of SN 2023wrk, a Luminous Type Ia Supernova with Significant Unburned Carbon in the Outer Ejecta

First detected on 2023 November 4 by the Gravitational-wave Optical Transient Observer, SN 2023wrk is a Type Ia Supernova at 40 Mpc, with significant unburned carbon in the outer ejecta. In this note, we present photometric and spectroscopic observations and analysis conducted by the Global Rapid Advanced Network Devoted to the Multi-messenger Addict over a 115 days period, which includes 78 days of measurements. The observations were contributed by both amateur and professional astronomers. J. Liu et al. analyzed the physical processes involved, and compared the evolution of color and spectral lines. We conclude that SN 2023wrk is the second 1999aa-like object with strong carbon absorption lines that has ever been found, which enriches our understanding of the subclass of 1999aa-like SNe.

Scylla. I. A Pure-parallel, Multiwavelength Imaging Survey of the ULLYSES Fields in the LMC and SMC

Scylla is a deep Hubble Space Telescope (HST) survey of the stellar populations, interstellar medium, and star formation in the LMC and SMC. As a pure-parallel complement to the Ultraviolet Legacy Library of Young Stars as Essential Standards (ULLYSES) survey, Scylla obtained 342 orbits of ultraviolet (UV) through near-IR imaging of the LMC and SMC with Wide Field Camera 3. In this paper, we describe the science objectives, observing strategy, data reduction procedure, and initial results from our photometric analysis of 96 observed fields. Although our observations were constrained by ULLYSES primary exposures, we imaged all fields in at least two filters (F475W and F814W) and 64% of fields in at least three and as many as seven WFC3 filters spanning the UV to IR. Overall, we reach average 50% completeness of m F225W = 26.0, m F275W = 26.2, m F336W = 26.9, m F475W = 27.8, m F814W = 25.5, m F110W = 24.7, and m F160W = 24.0 Vega mag in our photometric catalogs, which is faintward of the ancient main-sequence turnoff in all filters. The primary science goals of Scylla include characterizing the structure and properties of dust in the MCs, as well as their spatially resolved star formation and chemical enrichment histories. Our images and photometric catalogs, which represent the widest-area coverage of MCs with HST photometry to date, are available as a high-level science product at the Barbara A. Mikulski Archive for Space Telescopes.

A Statistical, Photometric, and SED Analysis to Characterize the BSS Populations in Old Open Cluster: Berkeley 39

ABSTRACT We present a statistical, photometric, and spectral energy distribution (SED) analysis to characterize the blue straggler stars (BSSs) populations in the Galactic old open cluster Berkeley 39. Berkeley 39 is a 6.16 Gyr old open cluster located at a distance of 3.99 Kpc.Gaia DR3 astrometry data have been used to estimate the membership probabilities using ensemble-based unsupervised machine learning techniques. We identified 21 BSS candidates on the colour–magnitude diagram, with 19 of them being detected in the Swift/UVOT UVW2 filter. We analysed the radial surface density profile and examined the cluster dynamical states and mass segregation effect. The SEDs of 19 BSSs are constructed using multiwavelength data covering UV to IR wavelengths. A single-component SED is fitted successfully for 14 BSS candidates. We discovered hot companions in five BSS candidates. These hot companions have temperatures of approximately 14 000 to 23 000 K, radii ranging from 0.04 to 0.13 R$_{\odot }$, and luminosities ranging from 0.16 to 2.91 L$_{\odot }$. Among these, three are most likely extremely low-mass white dwarfs (WDs) with masses around 0.17 to 0.18 M$_{\odot }$, and two are low-mass WDs with masses around 0.18 to 0.39 M$_{\odot }$. This confirms that they are post-mass transfer (Case A or Case B) systems. We also investigated the variable characteristics of BSSs by analysing their light curves using data from TESS. Our analysis confirms that two BSSs identified as eclipsing binaries in Gaia DR3 are indeed eclipsing binaries. Additionally, one of the two eclipsing binary BSSs shows evidence of having hot companions, as indicated by the multiwavelength SEDs.

Photometric and Kinematic Studies of Open Clusters Ruprecht 1 and Ruprecht 171

ABSTRACTThis study outlines a detailed investigation using CCD UBV and Gaia DR3 data sets of the two open clusters Ruprecht 1 (Rup‐1) and Ruprecht 171 (Rup‐171). Fundamental astrophysical parameters such as color excesses, photometric metallicities, ages, and isochrone distances were based on UBV‐data analyses, whereas membership probability calculations, structural and astrophysical parameters, as well as the kinematic analyses were based on Gaia DR3‐data. We identified 74 and 596 stars as the most probable cluster members with membership probabilities over 50% for Rup‐1 and Rup‐171, respectively. The color excesses were obtained as and mag for Rup‐1 and Rup‐171, respectively. Photometric metallicity analyses were performed by considering F‐G type main‐sequence member stars and found to be and dex for Rup‐1 and Rup‐171, respectively. Ages and distances were based on both UBV and Gaia‐data analyses; according to isochrone‐fitting these values were estimated to be Myr, pc for Rup‐1 and Myr, pc for Rup‐171. The present‐day mass function slope of Rup‐1 was estimated as and Rup‐171 as . Galactic orbit integration analyses showed that both of the clusters might be formed outside the solar circle.

KM UMa: An Active Short-period Detached Eclipsing Binary in a Hierarchical Quadruple System

Abstract The first detailed photometric and spectroscopic analysis of the G-type eclipsing binary KM UMa is presented, which indicates that the system is a short-period detached eclipsing binary. The radial velocity curves were calculated using the cross-correlation function method based on Large Sky Area Multi-Object Fiber Spectroscopic Telescope, Sloan Digital Sky Survey, and our observations, which determined the mass ratio as q = 0.45 (±0.04). Based on the light curves from the Transiting Exoplanet Survey Satellite, other survey data, and our multiband observations, the positive and negative O’Connell effects have been detected evolving gradually and alternately over the last 20 yr, which can be explained by the presence of spots on the primary component. A superflare event was detected in the SuperWASP data on 2007 February 28, further indicating that KM UMa is a very active system. We calculated its energy to be 5 × 1034 erg by assuming it occurred on the primary star. Utilizing hundreds of medium-resolution spectra and one low-resolution spectrum, the equivalent width variations of the H α line were calculated, indicating the presence of a 5.21 (±0.67) yr magnetic activity cycle. The orbital period variations were analyzed using the O–C method, detecting a long-term decrease superimposed with a periodic variation. The amplitude of the cyclic variation is 0.01124 (±0.00004) day, with a period of 33.66 (±0.0012) yr, which exceeds the 5.21 yr activity cycle, suggesting that this is more likely attributable to the light travel time effect of a third body. Simultaneously, a visual companion has been detected based on the Gaia astrometric data, indicating that KM UMa is actually in a 2+1+1 hierarchical quadruple system.

SN 2021wvw: A Core-collapse Supernova at the Subluminous, Slower, and Shorter End of Type IIPs

We present detailed multiband photometric and spectroscopic observations and analysis of a rare core-collapse supernova, SN 2021wvw, that includes photometric evolution up to 250 days and spectroscopic coverage up to 100 days postexplosion. A unique event that does not fit well within the general trends observed for Type IIP supernovae, SN 2021wvw shows an intermediate luminosity with a short plateau phase of just about 75 days, followed by a very sharp (∼10 days) transition to the tail phase. Even in the velocity space, it lies at a lower velocity compared to a larger Type II sample. The observed peak absolute magnitude is −16.1 mag in r-band, and the nickel mass is well constrained to 0.020 ± 0.006 M ⊙. Detailed hydrodynamical modeling using MESA+STELLA suggests a radially compact, low-metallicity, high-mass red supergiant progenitor (M ZAMS = 18 M ⊙), which exploded with ∼0.2 × 1051 erg s−1 leaving an ejecta mass of M ej ≈ 5 M ⊙. Significant late-time fallback during the shock propagation phase is also seen in progenitor+explosion models consistent with the light-curve properties. As the faintest short-plateau supernova characterized to date, this event adds to the growing diversity of transitional events between the canonical ∼100 days plateau Type IIP and stripped-envelope events.

The YMDB catalog: Young massive detached binaries for the determination of high-precision absolute stellar parameters

Context. Massive stars play a crucial role in the cosmic dynamics and chemical evolution of galaxies. Despite their significance, our understanding of their evolution and properties remains limited. An accurate determination of stellar parameters, such as the mass and radius, is essential for advancing our knowledge. Detached eclipsing binaries (DEBs) are particularly valuable for these determinations due to the minimal interaction between their stellar components, allowing for precise measurements. Aims. This study aims to introduce the Young Massive Detached Binary (YMDB) catalog, designed to address the gap in the high-precision absolute parameter determination for young massive stars. By focusing on DEBs within the spectral range O9-B1, this catalog seeks to provide a reliable database for future astronomical studies and improve our understanding of massive star evolution. Methods. We conducted a photometric analysis of 87 young massive stars in detached eclipsing systems using TESS light curves (LCs) that were processed through a custom pipeline. This analysis involved determining the amplitude of magnitude variations, orbital periods, times of minima, eccentricities, and the presence of apsidal motion and heartbeat phenomena. A thorough literature review was performed to obtain MK spectral classifications. We performed our own spectral classification of 19 systems to support the sample where a new classification was lacking or inconclusive. Results. The analysis identified 20 previously unreported binary systems, with 13 newly recognized as variable stars. Among the 87 stars examined, 30 are confirmed as YMDB members, and 25 are candidates pending spectral classification. The exclusion of the remaining 32 stars is attributed to unsuitable spectral types or their nondetached binary nature. Notable findings include the identification of new LC classifications, eccentricities in 13 systems, and heartbeat phenomena in several targets. Conclusions. The YMDB catalog offers a resource of high-quality LCs and reliable stellar classifications, serving as a valuable tool for the astronomical community.