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ABSTRACT Solar radio emission at low frequencies (<1 GHz) can provide valuable information on processes driving flares and coronal mass ejections (CMEs). Radio emission has been detected from active M dwarf stars, suggestive of much higher levels of activity than previously thought. Observations of active M dwarfs at low frequencies can provide information on the emission mechanism for high energy flares and possible stellar CMEs. Here, we conducted two observations with the Australian Square Kilometre Array Pathfinder Telescope totalling 26 h and scheduled to overlap with the Transiting Exoplanet Survey Satellite Sector 36 field, utilizing the wide fields of view of both telescopes to search for multiple M dwarfs. We detected variable radio emission in Stokes I centred at 888 MHz from four known active M dwarfs. Two of these sources were also detected with Stokes V circular polarization. When examining the detected radio emission characteristics, we were not able to distinguish between the models for either electron cyclotron maser or gyrosynchrotron emission. These detections add to the growing number of M dwarfs observed with variable low-frequency emission.
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The HST large programme on ω Centauri – IV. Catalogue of two external fields
ABSTRACT In the fourth paper of this series, we present – and publicly release – the state-of-the-art catalogue and atlases for the two remaining parallel fields observed with the Hubble Space Telescope for the large programme on ω Centauri. These two fields are located at ∼12 arcmin from the centre of the globular cluster (in the west and south-west directions) and were imaged in filters from the ultraviolet to the infrared. Both fields were observed at two epochs separated by about 2 yr that were used to derive proper motions and to compute membership probabilities.
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- Award ID(s):
- 2009193
- PAR ID:
- 10286690
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 505
- Issue:
- 3
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- 3549 to 3561
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/mnras/stab1476
