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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').
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"

28271 results found.

  1. GRB 250706A: Swift-XRT refined Analysis
  2. GRB 250706B: refined SVOM/MXT data analysis
  3. GRB 250706A: Swift/UVOT Upper Limits
  4. GRB 250706B: REM optical observations
  5. GRB 250706A: REM optical/NIR observations
  6. EP250706a/GRB 250706A: EP-WXT detection of a fast X-ray transient
  7. IceCube-250416A: DDOTI Optical Upper Limit
  8. IceCube-250706A: COLIBRÍ optical upper limits
  9. GRB 250706A: JinShan optical upper limits
  10. GRB 250706A: SAO RAS optical observations
  11. EP250704A: NOWT Detection
  12. GRB 250706A: SVOM/C-GFT upper limit in eary phase
  13. GRB250706B: Swift-XRT counterpart detection
  14. GRB 250706B: iTelescope optical observations
  15. EP250704a / GRB 250704B: end of optical plateau phase and rapid fading of the counterpart
  16. GRB 250706B: SVOM/VT optical observation
  17. GRB 250706B: TRT bright optical counterpart detection
  18. GRB 250706A: GROWTH-India Telescope optical upper limit
  19. GRB 250706B: SVOM detection of a long burst
  20. GRB 250706A: Swift detection of a burst
  21. GRB 250704B: Swift-XRT refined Analysis
  22. GRBs 250702B,C,D,E / EP250702a: J band upper limit by SYSU 80cm infrared telescope
  23. EP250702a/GRB250702 B,E,D: MeerKAT radio counterpart
  24. GRB 250703A: EIRSAT-1 GMOD Detection
  25. EP250702a/GRB 250702B,C,D,E: Archival radio observations from ASKAP VAST
  26. GRB 250704B: Swift/UVOT Upper Limits
  27. GRB 250704A: Swift/UVOT Detection
  28. LIGO/Virgo/KAGRA S250705cb: Identification of a GW compact binary merger candidate
  29. Radio observation of GRBs 250702B,C,E / EP250702a with the Allen Telescope Array
  30. EP250704a/GRB 250704B: GSP observations of the optical counterpart
  31. GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  32. EP250704a / GRB 250704B: NOT observations of the optical afterglow
  33. EP250704a/GRB 250704B VLT/HAWK-I NIR afterglow detection
  34. GRB 250702F: Kilonova-Catcher optical afterglow detection
  35. GRB 250702F: Monte Agliale Observatory optical observations
  36. GRB250702F: afterglow detected by joint EP-ZTF shadowing program
  37. EP250704a / GRB 250704B: JinShan optical observations
  38. EP250704a / GRB 250704B: SAO RAS optical observations
  39. EP250704a / GRB 250704B : GROWTH-India Telescope optical observations
  40. LIGO/Virgo/KAGRA S250704ab: NED Galaxies in the 3-Initial Localization Volume
  41. EP250704a: refined analysis of the EP-WXT and FXT follow-up observations
  42. LIGO/Virgo/KAGRA S250704ab: Upper limits from Fermi-GBM Observations
  43. GRB 250704A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 1.091
  44. EP250704a / GRB250704B: Swift-XRT counterpart detection
  45. GRB 250704A: Swift-XRT afterglow detection
  46. EP250704a / GRB 250704B - REM observations
  47. GRB 250702F: GROWTH-India Telescope optical observations
  48. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  49. GRB 250704A: REM retraction of optical afterglow detection and updated limit
  50. EP250702a: WFST optical observations
  51. EP250704a: COLIBRÍ optical counterpart candidate
  52. EP250704a: Einstein Probe detection of an X-ray transient
  53. GRB 250704A: REM detection of the optical afterglow
  54. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  55. LIGO/Virgo/KAGRA S250704ab: Identification of a GW compact binary merger candidate
  56. GRB 250704A: SVOM detection of a burst
  57. GRB 250702F: Swift/UVOT Detection
  58. Fermi GBM Analysis of GRB 250702B (formerly B,D,E); dissociation of C burst
  59. GRB 250702F: Swift-XRT refined Analysis
  60. GRB 250702F: Fermi GBM Observation
  61. GRB 250702F: Leavitt Observatory optical observations
  62. GRB 250702F: AKO Optical Afterglow Detection
  63. GRBs 250702B,C,D,E / EP250702a: VLT/HAWK-I NIR candidate
  64. GRBs 250702B,C,D,E / EP250702a: SVOM/GRM observation
  65. GRB 250702F: Skynet Optical Observations
  66. GRB 250424A: VIRT Optical Upper Limit
  67. GRB 250702B,C,D,E/EP250702a: COLIBRÍ optical upper limit
  68. GRB 250702F: TRT Optical Observation
  69. GRB 250703A: DDOTI Optical Upper Limit
  70. GRB 250702F: REM optical afterglow detection
  71. EP250702a: Global MASTER-Net observations report
  72. GRB 250702F: DDOTI Optical Observation
  73. GRB 250702F: COLIBRÍ Observations of the Afterglow
  74. EP250702a : an X-ray transient detected by Einstein Probe likely associated with GRB 250702B,C,D,E
  75. GRB 250702D, C, E: Swift/BAT-GUANO localization skymap of a burst or galactic transient
  76. GRB 250702F: Enhanced Swift-XRT position
  77. GRB 250702F: NOT observations of the optical afterglow
  78. GRB 250702F: Swift detection of a burst with an optical counterpart
  79. Fermi GBM Triggers 250702B, C, D and E are likely from the same source
  80. GRB 250702A: Fermi GBM Detection
  81. LIGO/Virgo/KAGRA S250702n: Identification of a GW compact binary merger candidate
  82. GRB 250702A: BALROG localization (Fermi Trigger 773142852 / GRB 250702413)
  83. LIGO/Virgo/KAGRA S250701bq: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S250701bp: Identification of a GW compact binary merger candidate
  85. GRB 250628B: Swift-XRT observations
  86. GRB 250628B: EP-FXT counterpart detection
  87. LIGO/Virgo/KAGRA S250629bs: Updated Sky localization
  88. LIGO/Virgo/KAGRA S250629ae: Updated Sky localization
  89. LIGO/Virgo/KAGRA S250629bs: Identification of a GW compact binary merger candidate
  90. LIGO/Virgo/KAGRA S250629ae: Identification of a GW compact binary merger candidate
  91. LIGO/Virgo/KAGRA S250628am: Updated Sky localization
  92. GRB 250628A: REM optical/NIR upper limits
  93. LIGO/Virgo/KAGRA S250628am: Identification of a GW compact binary merger candidate
  94. GRB 250628B: SVOM detection of a long burst
  95. GRB 250628A: VLT/X-shooter upper limits
  96. GRB 250628A: Swift/UVOT Upper Limits
  97. GRB 250628A: Swift-XRT refined Analysis
  98. GRB 250628A: Enhanced Swift-XRT position
  99. GRB 250628A: Swift detection of a burst
  100. GRB 250625A: Swift-BAT refined analysis

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