Investigators scrutinized blue straggler stars across 48 galactic globular clusters, representing a spectrum of magnitudes, ages, densities, separations, and compositions. This visual represents the contrast between a diffuse cluster and a concentrated cluster. (Image credit: ESA/Hubble & NASA)ShareShare by:
- Copy link
- X
Share this article 0Join the conversationFollow usAdd us as a favored source on GoogleNewsletterSubscribe to our newsletter
Cosmologists have addressed the enigma of why certain stars exhibit youthful radiance and a bluish hue, despite their age nearing that of the universe itself: They devour their stellar counterparts.
Identified as blue straggler stars, these age-defying astral entities have puzzled scientists for over seven decades. “Blue stragglers represent unusually substantial core hydrogen-consuming stars that, according to the doctrine of individual star progression, should not be in existence,” scholars noted in a report issued on Jan. 3 in the journal Nature Communications.
You may like
-
Rarrr! James Webb telescope spots ‘monster stars’ releasing nitrogen in the early cosmos
-
Unusual, ‘famished’ galaxy perished ‘a demise of 1,000 slashes’ in the ancient universe, JWST exposes
-
Mystifying, irradiated ‘mark’ in our galaxy might finally possess an explanation
Seeking Stars That Defy Age
Researchers formerly suggested that blue stragglers might arise through two mechanisms: intense impacts between two stars, or more nuanced interactions in binary systems as pairs of stars revolve around each other and swap gases.
The crew concluded that the latter situation is more plausible.
Galactic globular clusters furnish the optimal setting for scrutinizing stellar exchanges within gas-extracting binary configurations. These globular clusters feature thousands or millions of stars, bound by their combined gravitation. With such a multitude of stars residing within a span of merely tens or hundreds of light-years, clusters rank among the densest stellar settings in the universe. As such, they harbor numerous stellar crashes and a plethora of binary systems.
Clusters also boast remarkable antiquity. “Their duration approximates 12 [billion years], thereby resembling the age of the Universe,” which is 13.8 billion years in age, Francesco Ferraro, chief writer of the exploration and an astronomy lecturer at the University of Bologna in Italy, communicated to Live Science through email. “Indeed they constitute the most ancient demographic within our Galaxy.” This signifies that the individual stars within each cluster, which host the blue stragglers, originated during the epoch of galaxy formation.
More seasoned stars additionally radiate distinct wavelengths of radiation. Therefore, the scientists leveraged JWST’s ultraviolet filters to set apart blue stragglers from their older cluster-inhabitants — given that hotter, younger stars emit amplified radiation at abbreviated wavelengths compared to older, redder populations that radiate inadequately within this portion of the electromagnetic spectrum.
As per theory, blue straggler stars can arise in dual manners: by convergences of a pair of low-mass stars, or via a vampiric operation where a star pilfers gas from its cohort. An Astonishing Stellar Scenario
Perhaps paradoxically, the scientists determined that blue stragglers are scarcer in dense stellar milieus, despite these zones being more conducive to fostering engagements among stars. Instead, stragglers are notably more frequent in serene, low-density terrains where stars are distributed more extensively and “delicate binary systems are more prone to endure.”
The crew utilized a recognized, quantitative yardstick that correlates the quantity of blue stragglers with the host cluster’s attributes, akin to luminosity. This gauge unveiled that blue straggler populations differ substantially, ranging from three to 58 blue stragglers per unit of luminosity — matching the brilliance of 10,000 suns. Correspondingly, luminosity is connected to a cluster’s aggregate mass and, therefore, its density.
You may like
-
Rarrr! James Webb telescope spots ‘monster stars’ releasing nitrogen in the early cosmos
-
Unusual, ‘famished’ galaxy perished ‘a demise of 1,000 slashes’ in the ancient universe, JWST exposes
-
Mystifying, irradiated ‘mark’ in our galaxy might finally possess an explanation
Employing that analogous measure, the analysts ascertained that the count of typical stars inside a cluster stays comparatively uniform. This implies that stragglers and binary systems are singularly susceptible to the density of their surroundings.
“Jam-packed star clusters represent an unfriendly location for stellar partnerships,” study co-author Enrico Vesperini, an astronomer at Indiana University, conveyed in a statement. “Where space is scarce, binaries may be more readily obliterated, and the stars forfeit their prospects of remaining youthful.”
Consequently, dense environments, such as those nearer the centers of clusters, might not constitute the stellar speed-dating venues they were presumed to be. The gravitational forces from large stellar aggregates produce a cosmic-bumper-car-esque effect that disrupts binary systems prematurely in their progression, prior to their transition into blue straggler stars. As a consequence, the formation and endurance effectiveness of stragglers is amplified by 20-fold within more tranquil, low-density milieus, the scientists inferred.
A Novel Perspective on Stellar Development
Beyond resolving an astronomical conundrum, this exploration provides a “fresh avenue to comprehend how stars advance across billions of years,” study co-author Barbara Lanzoni, an astronomer at the University of Bologna, enunciated in the statement.
related stories
— ‘This isn’t featured in computer models’: Hubble maps turbulent past of Andromeda galaxy, exposing an unexpected narrative
— Hubble telescope uncovers ‘Cloud-9,’ a dark and uncommon ‘botched galaxy’ dissimilar to any precedent
— NASA’s Hubble telescope reveals most elaborate images of interstellar visitor 3I/ATLAS to date
Nevertheless, following eons, blue stragglers may not experience peaceful senescence. Owing to their substantial mass relative to their sibling stars, they exhibit a higher propensity to descend to the core of their clusters via a process termed dynamical friction. While this development is unfavorable for these tranquility-cherishing stars, astronomers can subsequently employ them as a “dynamical timepiece” to infer a cluster’s age hinged on the allocation of its blue stragglers.
In conclusion, these vigorous, youthful stars underscore a vibrant stellar equilibrium. Should they have originated with greater mass, they would have succumbed long ago as supernovas or white dwarfs. Their moderate dimensions, below 0.8 solar masses, have empowered them to persist long enough to rejuvenate their lifespans — at the detriment of devouring their siblings.
Article Sources
Ferraro, F.R., Lanzoni, B., Vesperini, E. et al. A binary-related origin mediated by environmental conditions for blue straggler stars. Nat Commun 17, 768 (2026). https://doi.org/10.1038/s41467-025-68159-5
TOPICSMilky WayNASAHubble Space TelescopeIvan FarkasLive Science Contributor
Ivan is a veteran scribe with a passion for mastering insights on technology, history, culture, and nearly every prime “ology” encompassing “anthro” through “zoo.” Ivan equally engages in internet-based humor, marketing collateral, and expert evaluations. A devotee of exercise science, during periods when Ivan isn’t fixated upon a book or screen he’s conceivably reveling within nature or hoisting steadily bulkier objects off terra firma. Ivan first emerged in picturesque Romania and presently abides within even-sunnier California.
Show More Comments
You must confirm your public display name before commenting
Please logout and then login again, you will then be prompted to enter your display name.
LogoutRead more
Rarrr! James Webb telescope spots ‘monster stars’ releasing nitrogen in the early cosmos
Unusual, ‘famished’ galaxy perished ‘a demise of 1,000 slashes’ in the ancient universe, JWST exposes
Mystifying, irradiated ‘mark’ in our galaxy might finally possess an explanation
‘A true transformation’: The James Webb telescope is revolutionizing our grasp of the hugest, most ancient black holes across the cosmos
‘One of those singular ‘astonishment’ instants’: Zombie star bordering Earth exhibits a rainbow shockwave that ‘shouldn’t be present’