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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

5182 results found.

  1. Fermi GRB 250307A: Global MASTER-Net observations report
  2. Fermi trigger No 762963055: Global MASTER-Net observations report
  3. LIGO/Virgo/KAGRA S250207bg: Update-5 NED Galaxies in the Localization Volume
  4. Konus-Wind detection of GRB 250222A
  5. IPN triangulation of GRB 250222A
  6. EP250302a: Global MASTER-Net observations report
  7. Fermi GRB 250302A: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S250206dm: early X-ray upper limits from Einstein Probe WXT and preliminary results of FXT observations
  9. EP250228a: Optical observations with Kinder and Swift/UVOT
  10. GRB 250225B: VLT/HAWKI near-infrared observations
  11. EP250223a: J band upper limit by SYSU 80cm telescope
  12. GRB 250205A / EP250205A: further radio observations with the VLA
  13. Fermi GRB 250226B: Global MASTER-Net observations report
  14. GRB 250221A: ATCA Detections and Upper Limits
  15. GRB 250225B: VLT/FORS2 candidate optical afterglow
  16. Fermi GRB 250226A: Global MASTER-Net observations report
  17. Fermi trigger No 762205158: Global MASTER-Net observations report
  18. Fermi GRB 250225A: Global MASTER-Net observations report
  19. LIGO/Virgo/KAGRA S250223dk and Swift/BAT-GUANO ID 762004910: DECam GW-MMADS candidates
  20. EP250223a: Kinder optical follow-up observations
  21. LIGO/Virgo/KAGRA S250223dk: DECam DESGW Candidates
  22. GOTO observations of LVK S250223dk/Swift-BAT RAVEN alert
  23. EP250223a: GOTO optical afterglow detections
  24. GRB 250222A: SVOM/GRM observation of a burst
  25. EP250223a: COLIBRÍ/DDRAGO Detection of the Optical Counterpart and Slow Fading
  26. EP250223a: REM NIR upper limit
  27. EP250223a: TRT optical afterglow observation
  28. LIGO/Virgo/KAGRA S250223dk: DDOTI Upper Limits on the Optical Counterpart
  29. Fermi trigger No 761805304: Global MASTER-Net observations report
  30. GRB 250221A: Swift-XRT refined Analysis
  31. IceCube-250207A: MASTER flaring blazar QSOJ0854+2006 with Zhirkov effect
  32. GRB 250220B: Fermi GBM Final Real-time Localization
  33. IPN triangulation of GRB 250217C (short)
  34. GRB 250215A: Swift-XRT refined Analysis
  35. GRB 250213A: SVOM detection of a burst
  36. Fermi trigger No 760945500: Global MASTER-Net observations report
  37. GRB 250211A: SVOM trigger sb25021103 is not a GRB
  38. LIGO/Virgo/KAGRA S250206dm: GECKO Continued Observaiton with 7DT
  39. LIGO/Virgo/KAGRA S250206dm: continued in SOAR galaxy targeted observations and identification of one possible transient
  40. LIGO/Virgo/KAGRA S250206dm: Gemini-North spectroscopic observation of AT2025bbo and its host galaxy
  41. GRB 250209A: MAXI/GSC detection (possible detection of an X-ray flare from 1RXS J145110.3+310648)
  42. LIGO/Virgo/KAGRA S250206dm: Global MASTER-Net observations report
  43. IceCube Alert 250207.09: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S250206dm: GECKO Observation with 7DT and KMTNet
  45. LIGO/Virgo/KAGRA S250206dm: ePESSTO+ classification of AT2025bar
  46. GRB 250207A: Swift-XRT refined Analysis
  47. LIGO/Virgo/KAGRA S250206dm: ATLAS observations of the skymap
  48. LIGO/Virgo/KAGRA S250206dm: SOAR galaxy targeted observations
  49. The EP-WXT trigger 01709131347 is likely a flaring star
  50. EP250205a/GRB 250205A: Einstein Probe observation
  51. GRB250205A: SVOM/VT optical afterglow detection
  52. GRB 250205A: SVOM detection of a burst
  53. Swift GRB250129A: MASTER 4 days observations report
  54. GRB 250129A: Liverpool Telescope observations suggest continued engine activity
  55. GRB 250129A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations
  56. GRB 250129A: NOT optical observations of continuining activity
  57. Ep250125A: 1.3m DFOT optical upper limit
  58. GRB 250129A: Swift-XRT refined Analysis
  59. GRB 250128B: VLT/HAWKI near-infrared observations
  60. Fermi GRB 250128B: Global MASTER-Net observations report
  61. GRB 250128B: Swift-XRT refined Analysis
  62. GRB 250128B: Swift detection of a short burst
  63. GRB 250127B: DDOTI Upper Limit on the Afterglow
  64. Fermi GRB 250127B: Global MASTER-Net observations report
  65. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  66. Fermi-LAT Gamma-ray Observations of IceCube-241224A
  67. EP250108a / SN2025kg: Non-detection from ATCA radio follow-up observations
  68. LIGO/Virgo/KAGRA S250105bn: 1 counterpart neutrino candidate event from an IceCube neutrino search
  69. GRB 241217A / EP241217B: radio detection with the VLA
  70. EP250108a: MeerKAT radio upper limit
  71. Konus-Wind detection of GRB 250113A
  72. IPN triangulation of GRB 250113A
  73. GRB 250114A: Swift-XRT refined Analysis
  74. GRB 250113A: INTEGRAL/SPI-ACS detection
  75. Swift GRB250114A: Global MASTER-Net OT detection
  76. GRB 250113A: SVOM/GRM observation of a long burst
  77. EP250111a: a new X-ray transient detected by Einstein Probe
  78. GRB 250108B: Swift-XRT refined Analysis
  79. GRB 250108B: Swift detection of a burst
  80. Fermi trigger No 757753930: Global MASTER-Net observations report
  81. GRB 250103B: Swift-XRT refined Analysis
  82. GRB 241229A: 1.3m DFOT upper limit
  83. GRB 241228B: 1.3m DFOT Optical observations
  84. GRB 250101A: further LCOGT optical afterglow observations
  85. GRB 250101A NUTTelA-TAO / BSTI Early Measurements
  86. GRB 250101A: GMG spectroscopic redshift at z ~ 2.481
  87. GRB 250101A: Swift-XRT refined Analysis
  88. GRB 250101A: SVOM/C-GFT early optical observations
  89. GRB 250101A: MASTER earlier OT observations with SOSS emission features
  90. GRB 250101A: Nanshan/HMT optical observations
  91. GRB 250101A: GMG Optical Observation
  92. GRB 250101A: Swift detection of a burst with an optical counterpart
  93. Swift GRB250101.56: Global MASTER-Net observations report
  94. GRB 241217a/EP241217b: ATCA Radio Detection
  95. GRB 241229A: EP-FXT X-ray afterglow confirmation
  96. GRB 241229B: SAO RAS optical upper limit
  97. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  98. Fermi GRB 241228B: Global MASTER-Net observations report
  99. GRB 241228A: Swift-XRT refined Analysis
  100. GRB 241228B: GOTO possible optical counterpart candidate

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