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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"

26719 results found.

  1. GRBs 250702B,C,D,E / EP250702a: J band upper limit by SYSU 80cm infrared telescope
  2. EP250702a/GRB250702 B,E,D: MeerKAT radio counterpart
  3. EP250702a/GRB 250702B,C,D,E: Archival radio observations from ASKAP VAST
  4. GRB 250704B: Swift/UVOT Upper Limits
  5. GRB 250704A: Swift/UVOT Detection
  6. LIGO/Virgo/KAGRA S250705cb: Identification of a GW compact binary merger candidate
  7. Radio observation of GRBs 250702B,C,E / EP250702a with the Allen Telescope Array
  8. Konus-Wind detection of GRB 250703A
  9. GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  10. Konus-Wind detection of short/hard GRB 250704B/ EP250704a
  11. EP250704a / GRB 250704B: NOT observations of the optical afterglow
  12. EP250704a/GRB 250704B VLT/HAWK-I NIR afterglow detection
  13. GRB 250702F: Kilonova-Catcher optical afterglow detection
  14. GRB 250702F: Monte Agliale Observatory optical observations
  15. GRB250702F: afterglow detected by joint EP-ZTF shadowing program
  16. EP250704a / GRB 250704B: JinShan optical observations
  17. EP250704a / GRB 250704B: SAO RAS optical observations
  18. EP250704a / GRB 250704B : GROWTH-India Telescope optical observations
  19. EP250704a: refined analysis of the EP-WXT and FXT follow-up observations
  20. LIGO/Virgo/KAGRA S250704ab: Upper limits from Fermi-GBM Observations
  21. GRB 250704A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 1.091
  22. EP250704a / GRB250704B: Swift-XRT counterpart detection
  23. GRB 250704A: Swift-XRT afterglow detection
  24. Konus-Wind detection of GRB 250702F
  25. EP250704a / GRB 250704B - REM observations
  26. GRB 250702F: GROWTH-India Telescope optical observations
  27. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  28. GRB 250704A: REM retraction of optical afterglow detection and updated limit
  29. EP250702a: WFST optical observations
  30. EP250704a: COLIBRÍ optical counterpart candidate
  31. EP250704a: Einstein Probe detection of an X-ray transient
  32. GRB 250704A: REM detection of the optical afterglow
  33. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  34. LIGO/Virgo/KAGRA S250704ab: Identification of a GW compact binary merger candidate
  35. GRB 250704A: SVOM detection of a burst
  36. GRB 250702F: Swift/UVOT Detection
  37. GRB 250702A: CALET Gamma-Ray Burst Monitor detection
  38. Fermi GBM Analysis of GRB 250702B (formerly B,D,E); dissociation of C burst
  39. GRB 250702F: Swift-XRT refined Analysis
  40. GRB 250702F: Fermi GBM Observation
  41. GRB 250702F: Leavitt Observatory optical observations
  42. GRB 250702F: AKO Optical Afterglow Detection
  43. GRBs 250702B,C,D,E / EP250702a: VLT/HAWK-I NIR candidate
  44. GRBs 250702B,C,D,E / EP250702a: SVOM/GRM observation
  45. GRB 250702A: GECAM-B detection
  46. GRB 250702F: Skynet Optical Observations
  47. GRB 250424A: VIRT Optical Upper Limit
  48. GRBs 250702B/C/D/E / EP250702a: Swift XRT localization
  49. GRB 250702B,C,D,E/EP250702a: COLIBRÍ optical upper limit
  50. EP250702a/GRB 250702B, C, D, E: EP-FXT follow-up observation
  51. GRB 250702F: TRT Optical Observation
  52. GRB 250703A: DDOTI Optical Upper Limit
  53. GRBs 250702B,C,D,E / EP250702a: Konus-Wind detection of a hard X-ray transient activity
  54. GRB 250702F: REM optical afterglow detection
  55. GRB 250702F: DDOTI Optical Observation
  56. GRB 250702B,C,D,E / EP 250702a: MAXI/GSC detection
  57. GRB 250702F: COLIBRÍ Observations of the Afterglow
  58. EP250702a : an X-ray transient detected by Einstein Probe likely associated with GRB 250702B,C,D,E
  59. GRB 250702D, C, E: Swift/BAT-GUANO localization skymap of a burst or galactic transient
  60. GRB 250702F: Enhanced Swift-XRT position
  61. GRB 250702F: NOT observations of the optical afterglow
  62. GRB 250702F: Swift detection of a burst with an optical counterpart
  63. GRB 250702F: Fermi GBM Final Real-time Localization
  64. GRB 250702E: Fermi GBM Final Real-time Localization
  65. Konus-Wind detection of GRB 250627A
  66. GRB 250702A: Fermi GBM Detection
  67. GRB 250702C: Fermi GBM Final Real-time Localization
  68. LIGO/Virgo/KAGRA S250702n: Identification of a GW compact binary merger candidate
  69. GRB 250702B: Fermi GBM Final Real-time Localization
  70. GRB 250702A: Fermi GBM Final Real-time Localization
  71. LIGO/Virgo/KAGRA S250701bq: Identification of a GW compact binary merger candidate
  72. LIGO/Virgo/KAGRA S250701bp: Identification of a GW compact binary merger candidate
  73. GRB 250628B: Swift-XRT observations
  74. GRB 250628B: EP-FXT counterpart detection
  75. LIGO/Virgo/KAGRA S250629bs: Identification of a GW compact binary merger candidate
  76. LIGO/Virgo/KAGRA S250629ae: Identification of a GW compact binary merger candidate
  77. GRB 250628A: REM optical/NIR upper limits
  78. LIGO/Virgo/KAGRA S250628am: Identification of a GW compact binary merger candidate
  79. GRB 250628B: SVOM detection of a long burst
  80. GRB 250628A: VLT/X-shooter upper limits
  81. GRB 250628A: Swift/UVOT Upper Limits
  82. GRB 250628A: Swift-XRT refined Analysis
  83. GRB 250628A: Enhanced Swift-XRT position
  84. GRB 250628A: Swift detection of a burst
  85. GRB 250625A: Swift-BAT refined analysis
  86. GRB 250625A: Leavitt Observatory afterglow detection
  87. GRB 250625A: AbAO and INASAN Kislovodsk Optical Observations
  88. The EP-WXT trigger 01709179435 is likely a new outburst of the CV SS Cyg
  89. GRB 250625A: SVOM/C-GFT upper limit in early phase
  90. GRB 250625A: GECAM-B detection
  91. GRB 250625A: Swift/UVOT Upper Limits
  92. GRB 250625A: ABObservatory afterglow detection
  93. GRB 250625A: OHP/T193 optical detection
  94. GRB 250625A: COLIBRÍ optical observations
  95. GRB 250625A: Swift-XRT refined Analysis
  96. GRB 250625A: JinShan optical observations
  97. GRB250625A: Fermi GBM Observation
  98. GRB 250620B: Fermi GBM Observation
  99. GRB 250625A: SAO RAS possible optical afterglow
  100. GRB 250625A: Enhanced Swift-XRT position

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