| Download | - View final version: First detection of radio emission associated with a classical Cepheid (PDF, 1.2 MiB)
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| DOI | Resolve DOI: https://doi.org/10.3847/1538-3881/acb0c7 |
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| Author | Search for: Matthews, L. D.ORCID identifier: https://orcid.org/0000-0002-3728-8082; Search for: Evans, N. R.ORCID identifier: https://orcid.org/0000-0002-4374-075X; Search for: Rupen, M. P.1 |
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| Affiliation | - National Research Council of Canada. Herzberg Astronomy and Astrophysics
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| Funder | Search for: National Science Foundation; Search for: Chandra X-ray Center |
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| Format | Text, Article |
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| Subject | Cepheid variable stars; stellar mass loss; radio continuum emission; stellar atmospheres; stellar pulsations |
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| Abstract | We report the detection of 15 GHz radio continuum emission associated with the classical Cepheid variable star δ Cephei (δ Cep) based on observations with the Karl G. Jansky Very Large Array. Our results constitute the first probable detection of radio continuum emission from a classical Cepheid. We observed the star at pulsation phase ϕ ≈ 0.43 (corresponding to the phase of maximum radius and minimum temperature) during three pulsation cycles in late 2018 and detected statistically significant emission (>5σ) during one of the three epochs. The observed radio emission appears to be variable at a ≳10% level on timescales of days to weeks. We also present an upper limit on the 10 GHz flux density at pulsation phase ϕ = 0.31 from an observation in 2014. We discuss possible mechanisms that may produce the observed 15 GHz emission, but cannot make a conclusive identification from the present data. The emission does not appear to be consistent with originating from a close-in, late-type dwarf companion, although this scenario cannot yet be strictly excluded. Previous X-ray observations have shown that δ Cep undergoes periodic increases in X-ray flux during pulsation phase ϕ ≈ 0.43. The lack of radio detection in two out of three observing epochs at ϕ ≈ 0.43 suggests that either the radio emission is not linked with a particular pulsation phase, or else that the strength of the generated radio emission in each pulsation cycle is variable. |
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| Publication date | 2023-02-09 |
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| Publisher | IOP |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 08940431-0847-4660-b9af-3075d83aae13 |
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| Record created | 2024-06-04 |
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| Record modified | 2024-06-04 |
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