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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"

41872 results found.

  1. Konus-Wind detection of GRB 260604C
  2. GRB 260608A: Fermi GRB Observation
  3. GRB 260604C: AstroSat CZTI detection
  4. GRB 260604C: SVOM/ECLAIRs refined analysis
  5. GRB 260608A: SVOM/ECLAIRs refined analysis
  6. Konus-Wind detection of GRB 260607B
  7. GRB 260607B: GECAM-B observation
  8. GRB 260608C: Fermi GBM Final Real-time Localization
  9. GRB 260604C: further SAO RAS optical observations
  10. GRB 260607A: AT2026ong (GOTO26fqf) is a type-Ia SN
  11. GRB 260607A / GOTO26fqf / AT2026ong: COLIBRÍ optical observations
  12. GRB 260608B: Fermi GBM Final Localization
  13. GRB 260604C: SVOM/COLIBRÍ (FM-GFT) colour evolution and confirmation of the late rebrightening
  14. GRB 260604C: SVOM/C-GFT upper limit
  15. GRB 260607B: AstroSat CZTI detection
  16. GRB 260608A: SVOM detection of a burst
  17. GRB 260608A: Fermi GBM Final Real-time Localization
  18. EP260605a: EP-FXT follow-up observation
  19. GRB 260607A: TRT optical observations
  20. GRB 260604C: GRANDMA further observations
  21. GRB 260607A: GOTO tentative optical counterpart candidate GOTO26fqf / AT2026ong
  22. GRB 260604A: SVOM/GRM detection
  23. GRB 260604C: Mondy optical observations: evidence of a possible brightening
  24. GRB 260607B: Fermi GBM Observation
  25. GRB 260607B: Fermi-LAT detection
  26. GRB 260607B: Fermi GBM Final Localization Correction
  27. GRB 260604C: Simeiz Zeiss-1000 optical observations of the afterglow
  28. GRB 260604C: OPD1.6m - GRANDMA observations - detection
  29. GRB 260607A: Fermi GBM Final Real-time Localization
  30. GRB 260604C: GECAM-B observation
  31. GRB 260604C: 6 GHz VLA observations
  32. GRB 260604C: SAO RAS optical observations
  33. GRB 260604C: GRANDMA observations
  34. GRB 260604B: SVOM/GRM detection
  35. GRB 260605A: Insight-HXMT/HE detection
  36. GRB260603A: SVOM/ECLAIRs refined analysis
  37. EP260605a: Einstein Probe detection of a fast X-ray transient
  38. EP260603a: COLIBRÍ optical upper limit
  39. GRB 260604A: Glowbug gamma-ray detection
  40. GRB 260604C: LCO optical upper limit
  41. GRB 260604C: Liverpool Telescope optical detection
  42. The EP-WXT trigger 01709267001 is likely a flaring star
  43. EP260602d: EP-FXT follow-up observation
  44. EP260602c: EP-FXT follow-up observation
  45. GRB 260601B / EP260601a: AstroSat CZTI detection
  46. GRB 260527A/EP260527a: 6 GHz VLA observations
  47. GRB 260604C: GOTO detections of the optical afterglow
  48. GRB 260604C: Kilonova-Catcher optical afterglow detection
  49. GRB 260604C: SVOM/COLIBRÍ (FM-GFT) optical observations
  50. The EP-WXT trigger 01709266798 is likely a flaring star
  51. GRB 260604C: Jinshan optical observations
  52. GRB 260604C: Fermi GBM Observation
  53. EP260602d: J-band upper limit with WINTER
  54. EP260602b: J-band upper limit with WINTER
  55. GRB 260604C: LAST detection of optical counterpart candidate
  56. GRB 260604C: MASTER OT J145749.59+284903.0 optical counterpart discovery
  57. Fermi GRB 260604C: Global MASTER-Net observations report
  58. Fermi GRB 260604C: Global MASTER-Net observations report
  59. SVOM GRB260604.85: Global MASTER-Net observations report
  60. GRB 260604C: SVOM detection of a long burst
  61. GRB 260604C: Fermi GBM Final Real-time Localization
  62. GRB 260515A: SVOM/VT optical detection at about 18 days post trigger
  63. GRB 260603A: NOT optical observations
  64. GRB 260603A: Simeiz Zeiss-1000 optical upper limit
  65. GRB 260604B: Fermi GBM Final Real-time Localization
  66. GRB 260601A: CALET Gamma-Ray Burst Monitor detection
  67. EP260602a: EP-FXT follow-up observation
  68. EP260603a: Global MASTER-Net observations report
  69. EP260603a: Einstein Probe detection of a fast X-ray transient
  70. EP260602d: Optical Upper limits with kinder observations
  71. GRB 260604A: Fermi GBM Final Real-time Localization
  72. EP260602b: Liverpool Telescope observations
  73. EP260602a: Liverpool Telescope optical upper limits
  74. EP260602b: Liverpool Telescope and LCO observations
  75. GRB 260603B: Fermi GBM Final Localization
  76. EP260602a: GTC and Liverpool Telescope optical observations
  77. Konus-Wind detection of GRB 260601B/EP260601a
  78. GRB 260603A: EP-FXT follow-up observation
  79. EP260601a/GRB 260601B: EP-FXT follow-up observation
  80. GRB 260601B / EP260601a: Mondy optical upper limit
  81. EP260602b: EP-FXT follow-up observation
  82. GRB 260601B/EP260601a: Glowbug gamma-ray detection
  83. GRB 260603A: Kilonova-Catcher optical upper limit
  84. GRB 260603A: SVOM/VT optical observations
  85. EP260602a: NOT NIR J-band observations
  86. GRB 260603A: SVOM/COLIBRÍ (FM-GFT) photometric redshift z = 3.57
  87. EP260602d: Einstein Probe detection of a fast X-ray transient
  88. Fermi trigger No 802141998: Global MASTER-Net observations report
  89. GRB 260601A: SVOM/GRM observation of a short burst
  90. EP260602c: Einstein Probe detection of a fast X-ray transient
  91. GRB 260603A: SVOM/COLIBRÍ (GFT-FM) optical counterpart candidate
  92. EP260602a: COLIBRÍ optical observations
  93. GRB260601B/EP260601a: NOT near-infrared observations
  94. SVOM GRB260603.23: Global MASTER-Net observations report
  95. GRB 260603A: SVOM detection of a burst
  96. EP260602b: Einstein Probe detection of a fast X-ray transient
  97. GRB 260601B/EP260601a: Insight-HXMT detection
  98. Fermi GRB 260602B: Global MASTER-Net observations report
  99. Fermi GRB 260602B: Global MASTER-Net observations report
  100. EP260530a: Xinglong optical spectroscopy of EP260530a / AT 2026nwl

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