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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"

37258 results found.

  1. GRB 250807B: SVOM/VT optical observation
  2. GRB 250809A: LCOGT Optical Upper Limits
  3. GRB 250702B: Chandra X-ray Detection
  4. Fermi GRB 250808A: Global MASTER-Net observations report
  5. Fermi Gamma-ray Burst Monitor trigger 776449964/250809689 is not a GRB
  6. GRB 250808A: VLT X-shooter candidate counterpart
  7. GRB 250809A: Prompt enhanced Swift-XRT position
  8. GRB 250809A: Swift detection of a gamma ray burst
  9. GRB 250808A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  10. GRB 250808A: Fermi GBM Observation
  11. GRB 250808A: Swift-XRT candidate counterpart detection
  12. GRB 250807A: SVOM/VT optical continued observation
  13. EP-WXT trigger 01709195487: KAIT confirmation of the stellar flare
  14. GRB 250808A: SVOM detection of a long burst
  15. GRB 250808A: Fermi GBM Final Real-time Localization
  16. Konus-Wind detection of GRB 250807A
  17. GRB 250807B: Swift/UVOT Detection
  18. GRB 250807B: Kilonova-Catcher optical afterglow detection
  19. GRB 250807A: Swift/UVOT Detection
  20. GRB 250807A: Swift-XRT refined Analysis
  21. GRB 250807B: VLT/X-Shooter spectroscopic redshift z = 1.522
  22. GRB 250806A: SVOM/MXT refined analysis
  23. GRB 250806A: SVOM/ECLAIRs refined analysis
  24. GRB 250806A: Mondy optical observations, and nearby bright galaxy photometry
  25. GRB 250804B: Insight-HXMT detection
  26. GRB 250807A: SVOM/GRM observation
  27. GRB 250807A: AstroSat CZTI detection of bright long burst
  28. GRB 250807B: Swift-XRT refined Analysis
  29. GRB 250806A: NOT z-band upper limit and host galaxy candidate
  30. GRB 250807B: NTT optical observations
  31. GRB 250807A: SVOM/VT optical observation
  32. EP250806a: Upper limit from Fermi-GBM Observations
  33. GRB 250807B: Enhanced Swift-XRT position
  34. GRB 250807A: Enhanced Swift-XRT position
  35. GRB 250807B: Swift detection of a burst with an optical counterpart.
  36. GRB 250805A: Kilonova-Catcher optical upper limits
  37. GRB 250805A: Swift/UVOT Upper Limits
  38. GRB 250806A: Swift/UVOT U-band detection
  39. GRB 250807A: Swift detection of a burst with an optical counterpart
  40. GRB 250806A: EP-FXT observation
  41. GRB 250806A: J-band upper limit from WINTER
  42. GRB 250805A: Swift-BAT refined analysis
  43. GRB 250806A: KAIT optical upper limit
  44. GRB 250806A: SVOM/VT refined analysis
  45. GRB 250806A: Swift-XRT counterpart detection
  46. GRB 250806A: Kilonova-Catcher optical upper limits
  47. GRB 250806A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  48. GRB 250806A: SVOM/VT optical upper limit
  49. GRB 250806A: SVOM detection of a soft burst
  50. GRB 250805A: SVOM/VT optical counterpart
  51. GRB 250805A: ESO/VLT observations
  52. GRB 250805A: Swift-XRT refined Analysis
  53. GRB 250804B: Swift-XRT observations
  54. GRB 250805A: Enhanced Swift-XRT position
  55. GRB 250804C: AstroSat CZTI detection of a long burst
  56. GRB 250805A: TRT optical upper limits
  57. GRB 250805A: Swift-XRT observations
  58. GRB 250805A: Swift detection of a burst
  59. GRB 250804B: Tiled Swift observations
  60. GRB 250804B: SVOM/GRM observation of a short burst
  61. GRB 250804A: Fermi GBM Final Localization
  62. Fermi Gamma-ray Burst Monitor trigger 775945985/250803856 is not a GRB
  63. GRB 250702B: SMA observations
  64. LIGO/Virgo/KAGRA S250727dc: DECam GW-MMADS candidates
  65. EP250711a: CrAO and Assy optical observations
  66. LIGO/Virgo/KAGRA S250727dc: DECam DESGW Epoch 1 Candidates
  67. GRB 250727A: Swift-XRT afterglow confirmation and refined analysis
  68. LIGO/Virgo/KAGRA S250725j: DECam DESGW Epoch 1-2 Candidates
  69. LIGO/Virgo/KAGRA S250726ak: Upper limits from Swift/BAT-GUANO
  70. LIGO/Virgo/KAGRA S250725l: Upper limits from Swift/BAT-GUANO
  71. LIGO/Virgo/KAGRA S250727dc: Upper limits from Swift/BAT-GUANO
  72. GRB 250725A: AstroSat CZTI detection
  73. GRB 250727A: EP-FXT follow-up observation
  74. GRB 250725A: PRIME near-infrared observations
  75. GRB: Clarification on Gamma-Ray Burst Naming Convention
  76. GRB 250728A: Swift-XRT observations
  77. GRB 250727A: SVOM/ECLAIRs refined analysis
  78. GRB 250728A: COLIBRÍ optical upper limit
  79. GRB 250728A: Fermi GBM Observation
  80. GRB 250728A: Swift ToO observations
  81. GRB 250728A: Swift/BAT-GUANO arcminute localization of a short burst
  82. GRB 250727A: AST3-2 Upper limit
  83. GRB 250727A: EP-FXT counterpart detection
  84. GRB250727A: SVOM/VT optical upper limit
  85. GRB 250727A: Swift-XRT observations
  86. GRB 250727A: SVOM detection of a burst
  87. GRB 250725A: Swift-XRT refined Analysis
  88. GRB 250725A: Fermi GBM Observation
  89. GRB 250725A: Swift-BAT refined analysis
  90. Konus-Wind detection of GRB 250725A
  91. GRB 250725A: SVOM/GRM observation
  92. GRB 250725A: Global MASTER-Net: First Optical Synchronous Observatios of Short GRB.
  93. GRB 250725A: Swift/UVOT Upper Limits
  94. GRB 250725A: Fermi-LAT detection
  95. GRB 250725A: VLT/FORS2 spectroscopic redshift z = 5.26
  96. GRB 250725A: BOOTES-7 early optical detection
  97. GRB 250725A: SVOM/VT optical candidate
  98. GRB 250725A: MASTER-OAFA optical detection of very fast afterglow
  99. GRB 250725A: Enhanced Swift-XRT position
  100. GRB 250725A: Swift detection of a burst

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