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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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').
Advanced Search

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"

32509 results found.

  1. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  2. EP240625a: GRANDMA Optical Upper Limits
  3. EP240626a: EP-FXT detection of the X-ray emission
  4. GRB 240624A: Swift-BAT refined analysis
  5. Konus-Wind detection of GRB 240619A
  6. Fermi GRB 240625B: Global MASTER-Net observations report
  7. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  8. GRB 240625A: Fermi GBM Observation
  9. EP240625a: NOT optical counterpart candidate
  10. EP240625a: EP-FXT detection of the X-ray emission
  11. GRB 240624B: GRBAlpha detection
  12. GRB240624A: Fermi GBM Observation
  13. Swift GRB 240624A: Global MASTER-Net observations report
  14. GRB240615A: Gemini-North observations of the BAT and XRT positions
  15. Fermi GRB 240624A: Global MASTER-Net observations report
  16. GRB240615A: Gemini-North observations of the BAT and XRT positions
  17. GRB 240619A: detection of a radio counterpart with AMI-LA
  18. EP240618a: NOT further optical observations
  19. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  20. GRB 240619A: J-band detection with WINTER
  21. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  22. EP240618a: NOT optical counterpart candidate
  23. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  24. GRB 240529A: JinShan optical observations
  25. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  26. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  27. EP240618a: GSP optical upper limit
  28. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  29. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  30. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  31. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  32. IPN triangulation of GRB 240615A (short)
  33. X-ray transient EP240618a: Fermi/GBM non-detection
  34. GRB 240619A: GRBAlpha detection
  35. EP240618a: Swift/XRT upper limit
  36. EP240617a: tentative Swift/XRT detection of the afterglow
  37. GRB 240619A: Swift-XRT probable afterglow detection
  38. GRB 240619A: Swift ToO observations
  39. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  40. GRB 240619C: NuSTAR automated detection of the GRB
  41. GRB 240619A: Fermi GBM Observation
  42. Fermi GBM Sub-Threshold Detection of GRB 240619C
  43. GRB 240619A: GOTO candidate optical afterglow
  44. EP240618a: Abastumani optical observationsEP240618a
  45. GRB 240615A: NOT optical observations
  46. EP240618a: GRANDMA Optical Upper Limits
  47. EP240618a: TRT optical upper limit
  48. Fermi GRB 240619A: Global MASTER-Net observations report
  49. EP240617a: STEP/T80S optical limits
  50. GRB 240615A: possible transient detection from Wendelstein observations
  51. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  52. LIGO/Virgo/KAGRA S240615dg: Updated Sky localization
  53. LIGO/Virgo/KAGRA S240618ah: Updated Sky localization
  54. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  55. GRB240615A: 1.3m DFOT optical upper limit
  56. EP240617a is likely a GRB event
  57. LIGO/Virgo/KAGRA S240618ah: Identification of a GW compact binary merger candidate
  58. GRB 240615A: J-band upper limits from WINTER
  59. GRB 240615A: Fermi GBM Observation
  60. LIGO/Virgo/KAGRA S240615ea: Updated Sky localization
  61. GRB 240615A: GECAM detection
  62. X-ray transient EP240414a: Chandra late time observation
  63. GRB 240615A: FLWO-1.2m optical upper limits
  64. Fermi GRB 240616A: Global MASTER-Net observations report
  65. Konus-Wind detection of GRB 240615A (short/hard)
  66. GRB 240615A: GOTO optical upper limits
  67. GRB 240615A: Swift ToO observations
  68. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  69. LIGO/Virgo/KAGRA S240615ea: Identification of a GW compact binary merger candidate
  70. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  71. GRB 240603A: VZLUSAT-2 detection
  72. GRB 240612A: GRBAlpha detection
  73. Fermi GRB 240612B: Global MASTER-Net observations report
  74. Fermi GRB 240612A: Global MASTER-Net observations report
  75. GRB 240607A: GECAM detection of a bright long burst
  76. Fermi GRB 240611A: Global MASTER-Net observations report
  77. Konus-Wind detection of GRB 240607A
  78. EXO 0748-676: Swift-BAT refined analysis
  79. GRB 240529A: LBT optical detection and late temporal decay
  80. GRB 240529A : MITSuME Akeno optical afterglow detection
  81. Fermi GRB 240610A: Global MASTER-Net observations report
  82. IPN triangulation of GRB 240607A
  83. Fermi GRB 240608A: Global MASTER-Net observations report
  84. Konus-Wind detection of GRB 240606B
  85. Fermi GRB 240607A: Global MASTER-Net observations report
  86. GRB 240529A: NOEMA detection
  87. GRB 240607A: Fermi GBM Observation
  88. GRB 240606B: Fermi GBM Observation
  89. Swift Trigger 1235109: consistent with noise and not astrophysical
  90. GRB 240607A: AstroSat CZTI detection of bright long burst
  91. GRB 240607A: Fermi GBM detection of a very bright burst
  92. GRB 240529A: radio detection with AMI-LA
  93. GRB 240606B: GECAM-B detection a long burst
  94. GRB 240606B: Swift ToO observations
  95. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  96. Konus-Wind detection of GRB 240603A
  97. Fermi GRB 240604A: Global MASTER-Net observations report
  98. IPN triangulation of GRB 240531A (short)
  99. Fermi GRB 240605A: Global MASTER-Net observations report
  100. Fermi GRB 240605C: Global MASTER-Net observations report

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