New way to date globular clusters: Brown dwarf cooling sequences.
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| Title: | New way to date globular clusters: Brown dwarf cooling sequences. |
|---|---|
| Authors: | Gerasimov, Roman1 (AUTHOR) rgerasim@nd.edu |
| Source: | Astrophysics & Space Science. Apr2026, Vol. 371 Issue 4, p1-27. 27p. |
| Subjects: | Brown dwarf stars, Star clusters, Statistical bias, James Webb Space Telescope (Spacecraft), Age of stars, Space telescopes, Milky Way, Astronomical photometry |
| Abstract: | As the oldest building blocks of our Galaxy, globular clusters retain the archaeological footprint of the early stellar environments. Accurate absolute ages of globular clusters are required to interpret this ancient record. Existing dating techniques often produce precise but discordant ages, suggestive of systematic errors in excess of 1 Gyr. The James Webb Space Telescope (JWST) has unlocked a new dating method that leverages the cooling behavior of previously unobservable brown dwarf members. With a largely independent set of systematic errors, this new method provides a new consistency test for more established methodologies. I present a likelihood-based histogram-free method to derive globular cluster ages from multi-band JWST photometry of cluster members near and below the hydrogen-burning limit. By applying the method to a large set of simulated observations, I establish that formal age errors (i.e. errors based on measurement uncertainties alone) under 0.2 Gyr are attainable for nearby globular clusters. I also evaluate the significance of associated systematic effects, including the chemical heterogeneity of globular clusters (multiple populations), unresolved binary systems and uncertainties in brown dwarf cooling rates. As with other methods of age determination, systematic effects dominate the error budget (in selected cases, by over an order of magnitude), but may be reduced with more sophisticated analysis. Finally, I provide a lookup table for determining the number of observations, exposure times and temporal baselines required to estimate the age of a given cluster to a prescribed precision. [ABSTRACT FROM AUTHOR] |
| Copyright of Astrophysics & Space Science is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 193810001 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: New way to date globular clusters: Brown dwarf cooling sequences. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Gerasimov%2C+Roman%22">Gerasimov, Roman</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> rgerasim@nd.edu</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Astrophysics+%26+Space+Science%22">Astrophysics & Space Science</searchLink>. Apr2026, Vol. 371 Issue 4, p1-27. 27p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Brown+dwarf+stars%22">Brown dwarf stars</searchLink><br /><searchLink fieldCode="DE" term="%22Star+clusters%22">Star clusters</searchLink><br /><searchLink fieldCode="DE" term="%22Statistical+bias%22">Statistical bias</searchLink><br /><searchLink fieldCode="DE" term="%22James+Webb+Space+Telescope+%28Spacecraft%29%22">James Webb Space Telescope (Spacecraft)</searchLink><br /><searchLink fieldCode="DE" term="%22Age+of+stars%22">Age of stars</searchLink><br /><searchLink fieldCode="DE" term="%22Space+telescopes%22">Space telescopes</searchLink><br /><searchLink fieldCode="DE" term="%22Milky+Way%22">Milky Way</searchLink><br /><searchLink fieldCode="DE" term="%22Astronomical+photometry%22">Astronomical photometry</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: As the oldest building blocks of our Galaxy, globular clusters retain the archaeological footprint of the early stellar environments. Accurate absolute ages of globular clusters are required to interpret this ancient record. Existing dating techniques often produce precise but discordant ages, suggestive of systematic errors in excess of 1 Gyr. The James Webb Space Telescope (JWST) has unlocked a new dating method that leverages the cooling behavior of previously unobservable brown dwarf members. With a largely independent set of systematic errors, this new method provides a new consistency test for more established methodologies. I present a likelihood-based histogram-free method to derive globular cluster ages from multi-band JWST photometry of cluster members near and below the hydrogen-burning limit. By applying the method to a large set of simulated observations, I establish that formal age errors (i.e. errors based on measurement uncertainties alone) under 0.2 Gyr are attainable for nearby globular clusters. I also evaluate the significance of associated systematic effects, including the chemical heterogeneity of globular clusters (multiple populations), unresolved binary systems and uncertainties in brown dwarf cooling rates. As with other methods of age determination, systematic effects dominate the error budget (in selected cases, by over an order of magnitude), but may be reduced with more sophisticated analysis. Finally, I provide a lookup table for determining the number of observations, exposure times and temporal baselines required to estimate the age of a given cluster to a prescribed precision. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Astrophysics & Space Science is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1007/s10509-026-04563-7 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 27 StartPage: 1 Subjects: – SubjectFull: Brown dwarf stars Type: general – SubjectFull: Star clusters Type: general – SubjectFull: Statistical bias Type: general – SubjectFull: James Webb Space Telescope (Spacecraft) Type: general – SubjectFull: Age of stars Type: general – SubjectFull: Space telescopes Type: general – SubjectFull: Milky Way Type: general – SubjectFull: Astronomical photometry Type: general Titles: – TitleFull: New way to date globular clusters: Brown dwarf cooling sequences. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Gerasimov, Roman IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 04 Text: Apr2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 0004640X Numbering: – Type: volume Value: 371 – Type: issue Value: 4 Titles: – TitleFull: Astrophysics & Space Science Type: main |
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