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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"

15407 results found.

  1. GRB 250702B,D,E / EP250702a: 10 GHz detection with the VLA
  2. IceCube-250708A: Upper limits from a search for additional neutrino events in IceCube
  3. GRB 250706B/C: Insight-HXMT detection
  4. EP/WXT 01709181970: GOTO observations confirm stellar variability
  5. EP-WXT trigger 01709181970. confirmation of a stellar flare by BOOTES-6
  6. EP250704a/GRB 250704B: 10 GHz VLA detection
  7. GRB250702 B,D,E / EP250702a: MOSFIRE imaging of the afterglow
  8. IceCube-250706A: No Candidates from WINTER
  9. IPN triangulation of GRB 250706C (consistent with the GRB 250706B)
  10. IceCube-250706A: No Candidates from the Zwicky Transient Facility
  11. IceCube-250708A - IceCube observation of a high-energy neutrino candidate track-like event
  12. IceCube-250706A: Upper limits from a search for additional neutrino events in IceCube
  13. GRB 250706B/C: Konus-Wind analysis of the prompt emission
  14. GRB 250706B: SVOM observations interpreted as the afterglow of GRB 250706C
  15. Fermi-LAT Gamma-ray Observations of IceCube-250706A
  16. GRB 250706B/C: Fermi-LAT detection
  17. GRB 250704A: SVOM/COLIBRÍ (FM-GFT) optical observations
  18. EP250702a/GRB250702 B,D,E: GRANDMA Upper Limit
  19. EP250702a/ GRB 250702B: NuSTAR X-ray Observations
  20. GRB 250706C: Konus-Wind detection of a very bright GRB ~1200 s before GRB 250706B
  21. GRB 250702F: GRANDMA observations
  22. GRB 250706B: refined SVOM/MXT data analysis
  23. IceCube-250416A: DDOTI Optical Upper Limit
  24. GRB 250706A: JinShan optical upper limits
  25. EP250704A: NOWT Detection
  26. IceCube-250706A - IceCube observation of a high-energy neutrino candidate track-like event
  27. GRB 250706B: SVOM/VT optical observation
  28. GRB 250706B: SVOM detection of a long burst
  29. EP250702a/GRB250702 B,E,D: MeerKAT radio counterpart
  30. EP250702a/GRB 250702B,C,D,E: Archival radio observations from ASKAP VAST
  31. GRB 250704B: Swift/UVOT Upper Limits
  32. GRB 250704B: Insight-HXMT detection
  33. Konus-Wind detection of GRB 250703A
  34. GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  35. Konus-Wind detection of short/hard GRB 250704B/ EP250704a
  36. EP250704a / GRB 250704B: NOT observations of the optical afterglow
  37. GRB 250702F: Kilonova-Catcher optical afterglow detection
  38. GRB 250702F: Monte Agliale Observatory optical observations
  39. EP250704a / GRB 250704B : GROWTH-India Telescope optical observations
  40. GRBs 250702B,D,E / EP250702a: fast fading, extremely red counterpart
  41. EP250704a / GRB 250704B: Pan-STARRS iz-band imaging and photometry
  42. EP 250704a: BOOTES-5 optical detection
  43. LIGO/Virgo/KAGRA S250704ab: Upper limits from Fermi-GBM Observations
  44. GRB 250702A: Insight-HXMT detection
  45. EP250704a / GRB250704B: Swift-XRT counterpart detection
  46. GRB 250702B / EP2050702a: FTW optical and NIR observations
  47. Konus-Wind detection of GRB 250702F
  48. GRB 250702F: GROWTH-India Telescope optical observations
  49. EP250704a / GRB 250704B: VLT/FORS2 optical afterglow detection
  50. GRB 250704B: SVOM/GRM observation of a short burst
  51. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  52. GRB 250704A: SVOM detection of a burst
  53. GRB 250702F: Swift/UVOT Detection
  54. Fermi GBM Analysis of GRB 250702B (formerly B,D,E); dissociation of C burst
  55. GRBs 250702B,C,D,E / EP250702a: 2.2m CAHA optical upper limit
  56. GRB 250702F: Fermi GBM Observation
  57. GRB 250702F: Leavitt Observatory optical observations
  58. GRBs 250702B,C,D,E / EP250702a: SVOM/GRM observation
  59. GRB 250702A: GECAM-B detection
  60. GRB 250424A: VIRT Optical Upper Limit
  61. GRB 250702B,C,D,E/EP250702a: COLIBRÍ optical upper limit
  62. GRBs 250702B,C,D,E / EP250702a: Konus-Wind detection of a hard X-ray transient activity
  63. GRB 250702F: DDOTI Optical Observation
  64. GRB 250702F: COLIBRÍ Observations of the Afterglow
  65. GRB 250702F: NOT observations of the optical afterglow
  66. GRB 250702F: MASTER optical afterglow observation
  67. GRB 250702F: GOTO optical counterpart detection
  68. GRB 250702F: Swift detection of a burst with an optical counterpart
  69. Konus-Wind detection of GRB 250627A
  70. GRB 250702A: Fermi GBM Detection
  71. GRB 250628B: Swift-XRT observations
  72. GRB 250627A: Insight-HXMT detection
  73. GRB 250627A: SVOM/GRM detection of a short burst
  74. GRB 250628B: SVOM detection of a long burst
  75. GRB 250625A: VLT/X-shooter spectroscopic observations at the afterglow position
  76. GRB 250628A: VLT/X-shooter upper limits
  77. GRB 250625A: Leavitt Observatory afterglow detection
  78. GRB 250625A: AbAO and INASAN Kislovodsk Optical Observations
  79. GRB 250625A: GTC/OSIRIS+ spectroscopic observations of the potential host galaxy
  80. GRB 250625A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart
  81. GRB 250625A: SVOM/C-GFT upper limit in early phase
  82. GRB 250625A: GECAM-B detection
  83. GRB 250625A: Swift/UVOT Upper Limits
  84. GRB 250625A: OHP/T193 optical detection
  85. GRB 250625A: COLIBRÍ optical observations
  86. GRB 250625A: Fermi-LAT detection
  87. GRB 250625A: JinShan optical observations
  88. GRB250625A: Fermi GBM Observation
  89. GRB 250620B: Fermi GBM Observation
  90. GRB 250620A: AstroSat CZTI detection
  91. GRB 241018A: Maidanak optical observations
  92. GRB 250620C: AstroSat CZTI detection
  93. sb25061207/GRB 250612D - SVOM/ECLAIRs refined analysis
  94. GRB 250521A: VZLUSAT-2 detection
  95. Konus-Wind detection of GRB 250620C
  96. GRB 250621B: SVOM/GRM detection of a possible magnetar X-ray burst
  97. GRB 250620C: SVOM/GRM observation
  98. GRB 250620A: SVOM/GRM observation of a short burst
  99. GRB 250617B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  100. GRB 250619B: Fermi GBM Observation

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