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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"
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submitter:"Judith Racusin"

26483 results found.

  1. GRB 260601A: GECAM-B observation of a short burst
  2. GRB 260601B/EP260601a: J-band upper limit with WINTER
  3. EP260530a/AT 2026nwl: COLIBRÍ optical follow up
  4. GRB 260601B: CALET Gamma-Ray Burst Monitor detection
  5. GRB 260601B / EP260601a: NuSTAR detection of prompt emission
  6. EP260602a: Einstein Probe detection of a fast X-ray transient
  7. GRB 260601B/EP260601a: SVOM/VT optical observations
  8. GRB 260601B/EP260601a: GECAM-B analysis suggests a possible long duration Type I burst
  9. GRB 260601B: GECAM-B detection of a burst probably associated with EP260601a
  10. EP260601a: Einstein Probe detection of an X-ray transient
  11. EP-WXT trigger 01709266307 (EP260601a): COLIBRÍ optical observations
  12. EP-WXT trigger 01709266307 (EP260601a): JinShan optical counterpart detection
  13. GRB 260601A: Glowbug gamma-ray detection of a short burst
  14. GRB 260531B: Glowbug gamma-ray detection
  15. GRB 260601A: Fermi GBM Observation
  16. EP260530a/AT 2026nwl: COLIBRÍ optical observations
  17. GRB 260530C: SVOM/ECLAIRs detection of a burst through on-ground search
  18. GRB 260527A/EP260527a: Glowbug gamma-ray detection
  19. GRB 260531B: GECAM-B observation
  20. GRB 260518B: SVOM/ECLAIRs detection of a soft burst possibly associated with EP 260518a and AT 2026ndp
  21. GRB 260531C: Fermi GBM Final Localization Correction
  22. AT 2026nuz: COLIBRÍ optical observations
  23. IPN triangulation of GRB 260527A / EP260527a
  24. GRB 260530B: SVOM/GRM detection of a possible bright short GRB
  25. GRB 260527A / EP260527a: VLA radio detection
  26. GRB 260429B / EP260429a: COLIBRÍ optical counterpart candidate
  27. GRB 260529A: GOTO tentative optical afterglow candidate
  28. GRB 260527A/EP260527a: Insight-HXMT detection
  29. EP260526a: SVOM/VT optical upper limits
  30. GRB 260527A: CALET Gamma-Ray Burst Monitor detection
  31. EP260527a/GRB 260527A: EP-FXT follow-up observation
  32. GRB 260527A: GECAM-B detection of a short burst probably associated with EP260527a
  33. GRB 260526A: GECAM-B observation
  34. Konus-Wind detection of GRB 260527A (short/hard) ~4 min before EP260527a
  35. EP260526a: EP-FXT follow-up observation
  36. EP260527a: SVOM/VT optical observation
  37. EP260527a: COLIBRÍ optical detection
  38. EP260527a: Einstein Probe detection of a fast X-ray transient
  39. GRB 260524A: SVOM/ECLAIRs detection of a burst through on-ground search
  40. EP260526a: LCO optical upper limits
  41. EP260526a: Einstein Probe detection of a fast X-ray transient
  42. GRB 260525A: AstroSat CZTI detection
  43. EP260526.405: COLIBRÍ optical upper limits
  44. The EP-WXT trigger 01709266106 is not a real source
  45. GRB 260523B: AstroSat CZTI detection
  46. GRB 260523B: GECAM-B observation
  47. GRB 260522A: Fermi GBM Observation
  48. GRB 260522B: NuSTAR detection of prompt emission
  49. GRB 260522A: GOTO optical upper limit
  50. EP260518a: Einstein Probe detection of an sub-threshold X-ray transient with counterpart AT 2026ndp
  51. GRB 260522A: Fermi-LAT detection
  52. GRB 260519C: SVOM/GRM observation
  53. GRB 260511A: iTelescope T-75 optical detection
  54. GRB 260520B: SVOM/GRM observation
  55. GRB 260411B: TERI Gamma-ray detection
  56. GRB 260407A: TERI Gamma-ray detection
  57. GRB 260307A: TERI Gamma-ray detection
  58. GRB 260225D: TERI Gamma-ray detection
  59. GRB 251118A: TERI Gamma-ray detection
  60. GRB 251113A: TERI Gamma-ray detection
  61. GRB 260428A: TERI Gamma-ray detection
  62. Konus-Wind detection of GRB 260519C
  63. GRB 260509A: SVOM/ECLAIRs refined analysis
  64. GRB 260519D: Fermi GBM Final Localization Correction
  65. GRB 260519C: NuSTAR detection of prompt emission
  66. Konus-Wind detection of GRB 260518A
  67. GRB 260518A: AstroSat CZTI detection of a long burst
  68. GRB 260516D: SVOM/ECLAIRs refined analysis
  69. GRB 260515A: SVOM/ECLAIRs refined analysis
  70. GRB 260421B: radio detection with the VLA
  71. GRID detection of GRB 260511A
  72. GRB 260516D: EP-FXT follow-up observation
  73. GRB 260516D: GOTO optical counterpart detection
  74. GRB 260516D: LCO optical observations
  75. GRB 260515A: further Liverpool Telescope observations
  76. GRB 260516D: SVOM/COLIBRÍ (FM-GFT) optical observations
  77. GRB 260516D: GROWTH-India Telescope optical detection
  78. GRB 260516D: SVOM/VT optical bright candidate
  79. GRB 260516D: FRAM-ORM optical limit
  80. SVOM GRB260516D: Global MASTER-Net observations report
  81. GRB 260516D: SVOM possible detection of a burst
  82. Konus-Wind detection of GRB 260515A
  83. GRB 260515A: LCO optical counterpart detection
  84. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) optical observations
  85. GRB 260515A: EP-FXT follow-up observation
  86. EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  87. EP260514a: NOT optical counterpart confirmation
  88. EP260514a: TRT optical counterpart candidate
  89. EP260514a: SVOM/VT optical candidate
  90. GRB 260515A: SVOM/VT optical observations
  91. GRB 260515A: OHP/T193 optical observations
  92. EP260514a: COLIBRÍ optical upper limits
  93. GRID detection of GRB 260507A
  94. GRB 260515A: LCO optical observations
  95. SVOM GRB 260515A: Global MASTER-Net observations report
  96. GRB 260515A: NOT optical observations.
  97. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  98. GRB 260515A: SVOM/VT optical candidate from VHF data
  99. GRB 260515A: JinShan optical counterpart candidate
  100. GRB 260515A: SVOM detection of a burst

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