Open Cluster Study Research Articles

Tidal tails of open clusters

Context. Open clusters that emerged from the star-forming regions as gravitationally bound structures are subjected to star evaporation, ejection, and tidal forces throughout the rest of their lives. Consequently, they form tidal tails that can stretch kiloparsecs along the cluster’s orbit. Aims. Cluster members are typically found by searching for overdensities in some parameter space (positions and velocities or sometimes actions and orbital parameters of stars). However, this method is not effective at identifying stars located in the tidal tails far from the open cluster cores. We present a probabilistic method for finding distant cluster members without relying on a search for overdensities and apply it to 476 open clusters. Methods. First, we simulated the dissolution of a cluster and obtained a probability distribution (likelihood) describing where cluster members are to be found. The distribution of stars from the Gaia DR3 catalogue in high likelihood regions was then compared to the simulated stellar population of the Galaxy to define the membership probability of each star. Results. The survey of cluster members included all stars with a magnitude of G < 17.5 and larger clusters with an age of > 100 Myr within 3 kpc from the Sun. We successfully found stars with high membership probabilities in the tidal tails of most clusters. The recovered tidal tails stretch more than a kiloparsec from the cluster cores in some cases. We analysed the morphological properties of the tidal tails and demonstrated how properly normalised membership probabilities aid systematic studies of open clusters. Finally, we have published a catalogue of stars found in the tidal tails.

WIYN Open Cluster Study. XC. Radial-velocity Measurements and Spectroscopic Binary Orbits in the Open Cluster NGC 2506

NGC 2506 is a rich, intermediate-age (2.0 Gyr), metal-poor ([Fe/H] ∼ −0.2) open cluster. This work presents the results of 12,157 spectroscopic radial-velocity measurements of 2442 stars in the NGC 2506 field obtained over 41 yr, made as part of the WIYN Open Cluster Study. Radial-velocity measurements are complete for the population of proper-motion member stars brighter than a Gaia G magnitude of 15.5, in which 320 proper-motion and radial-velocity cluster members were identified. Within the observation limit of G < 16.5, 469 proper-motion and radial-velocity members were identified. This work reports on the characteristics of NGC 2506, including projected spatial distribution, radial-velocity dispersion, and virial mass. This work also presents orbital solutions for 49 binary members with periods between 1 and 7580 days. NGC 2506 has an incompleteness-corrected binary frequency for binaries with periods less than 104 days of 35% ± 5%. This work also discusses in detail the 14 blue stragglers stars of NGC 2506—finding at least 64% ± 21% to be in binaries, five yellow straggler stars, and several other stars of note.

Linear polarization study of open clusters in the anticenter direction: Signature of the spiral arms

Aims. Our objective is to investigate the distribution of dust and associated large-scale structures of the Galaxy using optical linear polarization measurements of various open clusters located at different distances in the Galactic anticenter direction. Methods. We present R-band linear polarization observations of stars toward five open clusters: Kronberger 1, Berkeley 69, Berkeley 71, Berkeley 19, and King 8 in the anticenter direction. The polarization observations were carried out using the ARIES (Aryabhatta Research Institute of Observational Sciences) IMaging POLarimeter mounted on the 104 cm Sampurnanand telescope of ARIES, Nainital, making it the first study to target the polarization observations toward distant clusters (~6 kpc). We combined the observed polarization data with the distance information from the Gaia space telescope to infer the dust distribution along the line of sight. Results. The variation in the degree of polarization and extinction with distance reveals multiple dust layers in each cluster direction. In addition, common foreground-dust layers detected toward different cluster directions highlight global features such as spiral arms. Our results show that the dust clouds at 2 kpc toward Berkeley 69 and Berkeley 71 coincide with the Perseus arm, while the dust layer at ~4 kpc toward the distant clusters Berkeley 19 and King 8 indicates the presence of the Outer arm. The large-scale dust distribution obtained by combining our polarization results with previous polarization studies of nearby open clusters suggests that the anticenter direction is characterized by a low-extinction homogeneous dust distribution with a somewhat uniform orientation of the plane-of-sky component of the magnetic field along the line of sight. Conclusions. Our study demonstrates that polarization is useful as a tool for studying the large-scale dust distribution and structural features where kinematic distance methods are inadequate and cannot provide accurate distances to the dust clouds. The global dust distribution in the anticenter direction shows signatures of the intervening spiral arms.

WIYN Open Cluster Study. XC. Barium Surface Abundances of Blue Straggler Stars in the Open Clusters NGC 7789 and M67

We investigate barium (Ba) abundances in blue straggler stars (BSSs) in two open clusters, NGC 7789 (1.6 Gyr) and M67 (4 Gyr), as signatures of asymptotic-giant-branch (AGB) mass transfer. We combine our findings with previous Ba abundance analyses of NGC 6819 (2.5 Gyr) and NGC 188 (7 Gyr). Out of 35 BSSs studied in NGC 7789, NGC 6819, and M67, 15 (43% ± 11%) are Ba enriched; no BSSs in NGC 188 are Ba enriched. The Ba abundances of enriched BSSs show an anticorrelation with cluster age, ranging from an enrichment of [Ba/Fe] ∼ +1.5 dex in NGC 7789 to [Ba/Fe] ∼ +1.0 dex in M67. The Ba-enriched BSSs all lie in the same region of the H-R diagram, irrespective of cluster age or distance from the main-sequence turnoff. Our data suggest a link between AGB donor mass and mass-transfer efficiency in BSSs, in that less massive AGB donors tend to undergo more conservative mass transfer. We find that 40% ± 16% of the Ba-enriched BSSs are in longer-period spectroscopic binaries with orbital periods less than 5000 days. Those Ba-enriched BSSs that do not exhibit radial-velocity variability suggest AGB mass transfer in wide binaries by either wind mass transfer or wind Roche-lobe overflow. Given the preponderance of long orbital periods in the BSSs of M67 and NGC 188 and the frequency of Ba enrichment in NGC 7789, NGC 6819, and M67, it may be that AGB mass transfer is the dominant mechanism of BSS formation in open clusters older than 1 Gyr.

Discovery of a Barium Blue Straggler Star in M67 and “Sighting” of Its White Dwarf Companion* * This is paper XV of the UVIT Open Cluster Study (UOCS).

We report the discovery of a barium blue straggler star (BSS) in M67, exhibiting enhancements in slow neutron-capture (s-)process elements. Spectroscopic analysis of two BSSs (WOCS 9005 & WOCS 1020) and four stars located near the main-sequence turn-off using GALAH spectra, showed that WOCS 9005 has a significantly high abundance of the s-process elements ([Ba/Fe] = 0.75 ± 0.08, [Y/Fe] = 1.09 ± 0.07, and [La/Fe] = 0.65 ± 0.06). The BSS (WOCS 9005) is a spectroscopic binary with a known period, eccentricity, and a suspected white dwarf (WD) companion with a kinematic mass of 0.5 M ⊙. The first “sighting” of the WD in this barium BSS is achieved through multiwavelength spectral energy distribution (SED) with the crucial far-UV data from the UVIT/AstroSat. The parameters of the hot and cool companions are derived using binary fits of the SED using two combinations of models, yielding a WD with T eff in the range 9750–15,250 K. Considering the kinematic mass limit, the cooling age of the WD is estimated as ∼60 Myr. The observed enhancements are attributed to a mass transfer (MT) from a companion asymptotic giant branch star, now a WD. We estimate the accreted mass to be 0.15 M ⊙, through wind accretion, which increased the envelope mass from 0.45 M ⊙. The detection of chemical enhancement, as well as the sighting of WD in this system, have been possible due to the recent MT in this binary, as suggested by the young WD.

A study of open clusters in the local galactic environment using Gaia DR3

A study of open clusters in the local galactic environment using Gaia DR3

Exploring NGC 2345: A Comprehensive Study of a Young Open Cluster through Photometric and Kinematic Analysis

We conducted a photometric and kinematic analysis of the young open cluster NGC 2345 using CCD UBV data from 2 m Himalayan Chandra Telescope, Gaia Data Release 3, Two Micron All-Sky Survey, and the Photometric All-Sky Survey data sets. We found 1732 most probable cluster members with membership probability higher than 70%. The fundamental and structural parameters of the cluster are determined based on the cluster members. The mean proper motion of the cluster is estimated to be μαcosδ = −1.34 ± 0.20 and μ δ = 1.35 ± 0.21 mas yr−1. Based on the radial density profile, the estimated radius is ∼12.′8 (10.37 pc). Using color–color and color–magnitude diagrams, we estimate the reddening, age, and distance to be 0.63 ± 0.04 mag, 63 ± 8 Myr, and 2.78 ± 0.78 kpc, respectively. The mass function slope for main-sequence stars is determined as 1.2 ± 0.1. The mass function slope in the core, halo, and overall region indicates a possible hint of mass segregation. The cluster’s dynamical relaxation time is 177.6 Myr, meaning ongoing mass segregation, with complete equilibrium expected in 100–110 Myr. Apex coordinates are determined as −40.°89 ± 0.12, − 44.°99 ± 0.15. The cluster’s orbit in the Galaxy suggests early dissociation into field stars due to its close proximity to the Galactic disk.

WIYN Open Cluster Study 89. M48 (NGC 2548) 2: Lithium Abundances in the 420 Myr Open Cluster M48 from Giants through K Dwarfs* * The WIYN Observatory is a joint facility of the University of Wisconsin−Madison, Indiana University, the National Optical Astronomy Observatory, and the University of Missouri. † †WIYN Open Cluster Study, Mathieu ().

We consider WIYN/Hydra spectra of 329 photometric candidate members of the 420 Myr old open cluster M48 and report lithium detections or upper limits for 234 members and likely members. The 171 single members define a number of notable Li-mass trends, some delineated even more clearly than in Hyades/Praesepe: the giants are consistent with subgiant Li dilution and prior MS Li depletion due to rotational mixing. A dwarfs (8600–7700 K) have upper limits higher than the presumed initial cluster Li abundance. Two of five late A dwarfs (7700–7200 K) are Li-rich, possibly due to diffusion, planetesimal accretion, and/or engulfment of hydrogen-poor planets. Early F dwarfs already show evidence of Li depletion seen in older clusters. The Li–T eff trends of the Li Dip (6675–6200 K), Li Plateau (6200–6000 K), and G and K dwarfs (6000–4000 K) are very clearly delineated and are intermediate to those of the 120 Myr old Pleiades and 650 Myr old Hyades/Praesepe, which suggests a sequence of Li depletion with age. The cool side of the Li Dip is especially well defined with little scatter. The Li–T eff trend is very tight in the Li Plateau and early G dwarfs, but scatter increases gradually for cooler dwarfs. These patterns support and constrain models of the universally dominant Li depletion mechanism for FGK dwarfs, namely rotational mixing due to angular momentum loss; we discuss how diffusion and gravity-wave-driven mixing may also play roles. For late G/K dwarfs, faster rotators show higher Li than slower rotators, and we discuss possible connections between angular momentum loss and Li depletion.

WIYN Open Cluster Study. LXXXVII. Hubble Space Telescope Ultraviolet Detection of Hot White Dwarf Companions to Blue Lurkers in M67

We present the results of our Hubble Space Telescope far-ultraviolet survey of the blue lurkers (BLs) in M67. We find evidence for two white dwarf (WD) companions among the BLs that are indicative of mass transfer from an evolved companion, one in WOCS 14020 and the other in WOCS 3001. The cooling ages of the WDs suggest that mass transfer in these systems occurred ∼300–540 Myr and ∼600–900 Myr ago, respectively. The rotation periods and cooling ages of the BLs are consistent with spin-up and subsequent single-star spin-down models, and binary evolution models yield plausible evolutionary pathways to both BLs via highly nonconservative mass transfer. We conclude that the BLs are lower-luminosity analogs to the classical blue stragglers.

A tale of caution: the tails of NGC 752 are much longer than claimed

ABSTRACT Understanding the exact extent and content of tidal tails of open clusters provides useful clues on how field stars populate the Milky Way. We reanalyse, using Gaia EDR3 data, the tails around the open cluster NGC 752. Compared to previous analyses, we look at a much wider region around the cluster and use first the convergent point method, coupled with a clustering analysis using dbscan. We find that the cluster, located 433 pc away and well described by a Plummer profile, has very long and asymmetric tails, extending more than 260 pc on the sky (from tip to tip) – four times larger than previously thought – and contains twice as many stars. Numerical models computed with petar serve as a guide and confirm our analysis. The tails follow the predictions from the models, but the trailing tail appears slightly distorted, possibly indicating that the cluster had a complicated history of galactic encounters. Applying an alternative method to the newly developed compact convergent point method, we potentially trace the cluster’s tidal tails to their full extent, covering several thousands of parsecs and more than 1000 stars. Our analysis therefore opens a new window on the study of open clusters, whose potential will be fully unleashed with future Gaia data releases.

WIYN open cluster study: The old open cluster, NGC 188, and a re-evaluation of Lithium-richness among red giants

ABSTRACT We present WIYN1/Hydra spectra of 34 red giant candidate members of NGC 188, which, together with WOCS2 and Gaia data yield 23 single members, 6 binary members, 4 single non-members, and 1 binary non-member. We report [Fe/H] for 29 members and derive [Fe/H]NGC188 = +0.064 ± 0.018 dex (σμ) (sky spectra yield A(Fe)⊙ = 7.520 ± 0.015 dex (σμ)). We discuss effects on the derived parameters of varying Yale-Yonsei isochrones to fit the turnoff. We take advantage of the coolest, lowest gravity giants to refine the line list near Li 6707.8 Å. Using synthesis we derive detections of A(Li)3 = 1.17, 1.65, 2.04, and 0.60 dex for stars 4346, 4705, 5027, and 6353, respectively, and 3σ upper limits for the other members. Whereas only two of the detections meet the traditional criterion for ‘Li-richness’ of A(Li) &amp;gt; 1.5 dex, we argue that since the cluster A(Li) vanish as subgiants evolve to the base of the RGB, all four stars are Li-rich in this cluster’s context. An incidence of even a few Li-rich stars in a sample of 29 stars is far higher than what recent large surveys have found in the field. All four stars lie either slightly or substantially away from the cluster fiducial sequence, possibly providing clues about their Li-richness. We discuss a number of possibilities for the origin for the Li in each star, and suggest potentially discriminating future observations.

The Gaia-ESO Survey: The analysis of the hot-star spectra

Context. The Gaia-ESO Survey (GES) is a large public spectroscopic survey that has collected, over a period of six years, spectra of ~105 stars. This survey provides not only the reduced spectra, but also the stellar parameters and abundances resulting from the analysis of the spectra. Aims. The GES dataflow is organised in 19 working groups. Working group 13 (WG13) is responsible for the spectral analysis of the hottest stars (O, B, and A type, with a formal cutoff of Teff &gt; 7000 K) that were observed as part of GES. We present the procedures and techniques that have been applied to the reduced spectra in order to determine the stellar parameters and abundances of these stars. Methods. The procedure used was similar to that of other working groups in GES. A number of groups (called Nodes) each independently analyse the spectra via state-of-the-art techniques and codes. Specific for the analysis in WG13 was the large temperature range covered (Teff ≈ 7000–50 000 K), requiring the use of different analysis codes. Most Nodes could therefore only handle part of the data. Quality checks were applied to the results of these Nodes by comparing them to benchmark stars, and by comparing them to one another. For each star the Node values were then homogenised into a single result: the recommended parameters and abundances. Results. Eight Nodes each analysed part of the data. In total 17 693 spectra of 6462 stars were analysed, most of them in 37 open star clusters. The homogenisation led to stellar parameters for 5584 stars. Abundances were determined for a more limited number of stars. The elements studied are He, C, N, O, Ne, Mg, Al, Si, and Sc. Abundances for at least one of these elements were determined for 292 stars. Conclusions. The hot-star data analysed here, as well as the GES data in general, will be of considerable use in future studies of stellar evolution and open clusters.

Open clusters with proper motions fully separatedfrom the field stars using Gaia DR2

ABSTRACT The study of open star clusters makes us understand a lot about the composition and construction of the Milky Way Galaxy. Thanks to the Gaia DR2 database that helps us to get the genetic members of star clusters using their proper motions and parallaxes, and estimating their physical properties in a very accurate way. This study aims to detect the reasons that make clusters (within 2 kpc) have proper motions completely separated from the background field stars. We studied a large sample of open stellar clusters taken from Dias’s catalogue and drew the vector point diagrams using the astrometric data of Gaia DR2. By visual inspection, we specified 108 objects as separated clusters and 377 ones as melted clusters. We studied their mean parameters in the four galactic quadrants of the Milky Way Galaxy.

Mapping the Galactic Metallicity Gradient with Open Clusters: The State-of-the-Art and Future Challenges

In this paper, we make use of data collected for open cluster members by high-resolution spectroscopic surveys and programmes (i.e., APOGEE, Gaia-ESO, GALAH, OCCASO, and SPA). These data have been homogenised and then analysed as a whole. The resulting catalogue contains [Fe/H] and orbital parameters for 251 Galactic open clusters. The slope of the radial metallicity gradient obtained through 175 open clusters with high-quality metallicity determinations is −0.064 ± 0.007 dex kpc−1. The radial metallicity distribution traced by open clusters flattens beyond RGal = 12.1 ± 1.1 kpc. The slope traced by open clusters in the [Fe/H]-Lz diagram is −0.31 ± 0.02 × 103 dex km−1 kpc−1 s, but it flattens beyond Lz = 2769 ± 177 km kpc s−1. In this paper, we also review some high-priority practical challenges around the study of open clusters that will significantly push our understanding beyond the state-of-the-art. Finally, we compare the shape of the galactic radial metallicity gradient to those of other spiral galaxies.

UOCS – VI. UVIT/AstroSat detection of low-mass white dwarf companions to four more blue stragglers in M67

ABSTRACTBlue straggler stars (BSSs) in M67 have attracted attention from observations and theory to unravel their formation mechanisms. In the series of Ultra Violet Imaging Telescope (UVIT on AstroSat) study of Open clusters (UOCS), here we report the detection of hot companions to 4 more BSSs (WOCS 2013, WOCS 3013, WOCS 4006, and WOCS 5005), using Far-UV photometry obtained in two epochs from UVIT. We characterize the hot companions to be low to extremely low mass (LM/ELM) white dwarfs (WDs) with Teff ∼ 13–23 kK, R/R⊙ ∼ 0.035–0.051, M/M⊙ ∼ 0.19–0.3, and age ∼25–300 Myr using WD models. Two BSSs (WOCS 1025 and WOCS 3005) showed UV excess, and may have a hot companion, but we are unable to confirm/characterize. 13 BSSs are detected by UVIT in the two epochs of data, of the total 14 present in M67. We have performed detailed analysis on 10 BSSs, including our previous studies. Five BSSs are found to have LM/ELM WD companions, suggesting Case-B mass-transfers (MT) to be prevalent in M67 (with a lower limit of 37.5 per cent, 5/14), along with other mechanisms. Three BS+WD systems have orbital parameters outside the limit for stable MT as per the models. We speculate the following three possibilities – their orbits are altered due to cluster dynamics, some may be in triple systems with LM/ELM WDs in an unknown closer orbit, or a modified MT mechanism may be required to enable their formation.

Stellar Radial Velocities in the Old Open Cluster M67 (NGC 2682). II. The Spectroscopic Binary Population

Abstract We present and analyze 120 spectroscopic binary and triple cluster members of the old (4 Gyr) open cluster M67 (NGC 2682). As a cornerstone of stellar astrophysics, M67 is a key cluster in the WIYN Open Cluster Study (WOCS); radial-velocity (RV) observations of M67 are ongoing and extend back over 45 yr, incorporating data from seven different telescopes, and allowing us to detect binaries with orbital periods ≲104 days. Our sample contains 1296 stars (604 cluster members) with magnitudes of 10 ≤ V ≤ 16.5 (about 1.3–0.7 M ⊙), from the giants down to ∼4 mag below the main-sequence turnoff, and extends in radius to 30′ (7.4 pc at a distance of 850 pc, or ∼7 core radii). This paper focuses primarily on the main-sequence binaries, but orbital solutions are also presented for red giants, yellow giants, and sub-subgiants. Out to our period detection limit and within our magnitude and spatial domain, we find a global main-sequence incompleteness-corrected binary fraction of 34% ± 3%, which rises to 70% ± 17% in the cluster center. We derive a tidal circularization period of . We also analyze the incompleteness-corrected distributions of binary orbital elements and masses. The period distribution rises toward longer periods. The eccentricity distribution, beyond P circ, is consistent with a uniform distribution. The mass-ratio distribution is also consistent with a uniform distribution. Overall, these M67 binaries are closely consistent with similar binaries in the galactic field, as well as with the old (7 Gyr) open cluster NGC 188. WOCS. 83.

WIYN Open Cluster Study. LXXXIV. The Effect of Chromospheric Activity on Oxygen Abundances from the 7774 Å Triplet in Pleiades Dwarfs

Abstract We present a spectroscopic analysis of 7774 Å O i triplet abundances, 8498–8662 Å Ca ii triplet chromospheric activity, and rotation in the Pleiades open cluster, with the objective of thoroughly examining the O triplet overabundance trends observed in cool open cluster dwarfs, and to thereby make clear the cause of that trend. High-dispersion, contemporaneous spectra of the O i triplet, Ca ii triplet, and Hα spectral regions in 41 Pleiades dwarfs were acquired using Hydra on the WIYN 3.5 m telescope. Our Ca ii emission equivalent-width data exhibit a strong positive correlation with decreasing T eff, with the rapidly rotating stars enhanced by up to 50% above the slowly rotating stars. Our triplet [O/H] values exhibit a statistically significant positive correlation with total Ca ii triplet emission, and similarly, significant correlations have been found by every study to date that used contemporaneous O triplet abundance and chromospheric activity data, which is strong evidence that chromospheric activity is the cause of the observed overabundance trends. Based on the slowly rotating, low Ca ii emission stars in the near-solar range 5450 K &lt; T eff &lt; 6100 K, we find a cluster mean [O/H] = + 0.143 ± 0.061, consistent with the substantial super-solar [O/H] values exhibited by most young ( &lt; 1 Gyr) open clusters. We also find a cluster mean [Fe/H] = + 0.029 ± 0.034, in excellent agreement with previous studies.

The Gaia-ESO Survey: Calibrating the lithium–age relation with open clusters and associations

Context. Previous studies of open clusters have shown that lithium depletion is not only strongly age dependent but also shows a complex pattern with other parameters that is not yet understood. For pre- and main-sequence late-type stars, these parameters include metallicity, mixing mechanisms, convection structure, rotation, and magnetic activity. Aims. We perform a thorough membership analysis for a large number of stars observed within the Gaia-ESO survey (GES) in the field of 20 open clusters, ranging in age from young clusters and associations, to intermediate-age and old open clusters. Methods. Based on the parameters derived from the GES spectroscopic observations, we obtained lists of candidate members for each of the clusters in the sample by deriving radial velocity distributions and studying the position of the kinematic selections in the EW(Li)-versus-Teff plane to obtain lithium members. We used gravity indicators to discard field contaminants and studied [Fe/H] metallicity to further confirm the membership of the candidates. We also made use of studies using recent data from the Gaia DR1 and DR2 releases to assess our member selections. Results. We identified likely member candidates for the sample of 20 clusters observed in GES (iDR4) with UVES and GIRAFFE, and conducted a comparative study that allowed us to characterize the properties of these members as well as identify field contaminant stars, both lithium-rich giants and non-giant outliers. Conclusions. This work is the first step towards the calibration of the lithium–age relation and its dependence on other GES parameters. During this project we aim to use this relation to infer the ages of GES field stars, and identify their potential membership to young associations and stellar kinematic groups of different ages.

IBSE-Type Astronomy Projects Using Real Data

AbstractI present three examples of IBSE (Inquiry-Based Science Education) type activities for students and teachers using data and resources from the Faulkes Telescope Project and the National Schools’ Observatory. Both projects have recently celebrated their 15th anniversary and both provide free access via the internet to 2-metre robotic telescopes to educational users throughout the World. Each activity contains supporting material and sample datasets in several aspects of astronomy as well as instructions on how to analyse data. These activities are designed to be ‘teacher-free’, extended projects for students.They include the study of open clusters via astronomical images and population studies of exoplanets. I also present a Citizen Science project using data from Type Ia supernovae as discovered by the Gaia Alerts consortium. These data allow citizen scientists to develop their own Hubble Plot and begin to understand the link between Type Ia supernovae and the age of the Universe.

UVIT Open Cluster Study. II. Detection of Extremely Low Mass White Dwarfs and Post–Mass Transfer Binaries in M67

Abstract A detailed study of the UV-bright stars in the old open star cluster M67 is presented based on the far-UV observations using the Ultra Violet Imaging Telescope (UVIT) on ASTROSAT. The UV and UV–optical color–magnitude diagrams (CMDs), along with overlaid isochrones, are presented for the member stars, which include blue straggler stars (BSSs), triple systems, white dwarfs (WDs), and spectroscopic binaries. The CMDs suggest the presence of excess UV flux in many members, which could be extrinsic or intrinsic to them. We construct multiwavelength spectral energy distributions (SEDs) using photometric data from the UVIT, Gaia DR2, Two Micron All Sky Survey, and Wide-Field Infrared Survey Explorer surveys, along with optical photometry. We fitted model SEDs to seven WDs and find that four of them have mass &gt;0.5 M ⊙ and cooling age of less than 200 Myr, thus demanding BSS progenitors. SED fits to 23 stars detect extremely low mass (ELM) WD companions to WOCS2007, WOCS6006, and WOCS2002 and a low-mass WD to WOCS3001, which suggest these to be post–mass transfer (MT) systems. Twelve sources with possible WD companions need further confirmation. Nine sources have X-ray and excess UV flux, possibly arising out of stellar activity. This study demonstrates that UV observations are key to detecting and characterizing the ELM WDs in nondegenerate systems, which are ideal test beds to explore the formation pathways of these peculiar WDs. The increasing detection of post-MT systems among BSSs and main-sequence stars suggests a strong MT pathway and stellar interactions in M67.