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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

45721 results found.

  1. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  2. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  3. Swift GRB 240624A: Global MASTER-Net observations report
  4. GRB240615A: Gemini-North observations of the BAT and XRT positions
  5. Fermi GRB 240624A: Global MASTER-Net observations report
  6. GRB 240624B: Fermi GBM Final Real-time Localization
  7. Fermi trigger No 740949590: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S240624cd: Retraction of GW unmodeled transient candidate
  9. GRB240615A: Gemini-North observations of the BAT and XRT positions
  10. GRB 240624A: Fermi GBM Final Real-time Localization
  11. GRB 240619A: detection of a radio counterpart with AMI-LA
  12. GRB 240624A: Swift detection of a burst
  13. LIGO/Virgo/KAGRA S240623dg: Retraction of GW compact binary merger candidate
  14. EP240618a: NOT further optical observations
  15. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  16. GRB 240619A: J-band detection with WINTER
  17. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  18. Fermi trigger No 740744838: Global MASTER-Net observations report
  19. EP240618a: NOT optical counterpart candidate
  20. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  21. GRB 240529A: JinShan optical observations
  22. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  23. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  24. EP240618a: GSP optical upper limit
  25. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  26. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  27. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  28. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  29. IPN triangulation of GRB 240615A (short)
  30. X-ray transient EP240618a: Fermi/GBM non-detection
  31. GRB 240619A: GRBAlpha detection
  32. EP240618a: Swift/XRT upper limit
  33. EP240617a: tentative Swift/XRT detection of the afterglow
  34. GRB 240619A: Swift-XRT probable afterglow detection
  35. GRB 240619A: Swift ToO observations
  36. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  37. GRB 240619C: NuSTAR automated detection of the GRB
  38. GRB 240619A: Fermi GBM Observation
  39. Fermi GBM Sub-Threshold Detection of GRB 240619C
  40. GRB 240619A: GOTO candidate optical afterglow
  41. EP240618a: Abastumani optical observationsEP240618a
  42. GRB 240615A: NOT optical observations
  43. EP240618a: GRANDMA Optical Upper Limits
  44. GRB 240619C: AstroSat CZTI detection
  45. EP240618a: TRT optical upper limit
  46. Fermi trigger No 740474239: Global MASTER-Net observations report
  47. Fermi GRB 240619A: Global MASTER-Net observations report
  48. EP240617a: STEP/T80S optical limits
  49. GRB 240615A: possible transient detection from Wendelstein observations
  50. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  51. LIGO/Virgo/KAGRA S240615dg: Updated Sky localization
  52. LIGO/Virgo/KAGRA S240618ah: Updated Sky localization
  53. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  54. EP240618a: BOOTES-6/DPRT optical upper limit
  55. Fermi Gamma-ray Burst Monitor trigger 740474239/240619304 is not a GRB
  56. GRB 240619B: Fermi GBM Final Real-time Localization
  57. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  58. Fermi trigger No 740430582: Global MASTER-Net observations report
  59. GRB240615A: 1.3m DFOT optical upper limit
  60. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  61. GRB 240619A: Fermi GBM Final Real-time Localization
  62. EP240617a: BOOTES-6/DPRT optical upper limit
  63. EP240617a is likely a GRB event
  64. EP240617a: EP-WXT detection of a fast X-ray transient
  65. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  66. LIGO/Virgo/KAGRA S240618ah: Identification of a GW compact binary merger candidate
  67. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  68. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  69. GRB 240615A: J-band upper limits from WINTER
  70. GRB 240615A: Fermi GBM Observation
  71. LIGO/Virgo/KAGRA S240615ea: Updated Sky localization
  72. GRB 240615A: Swift-XRT observations
  73. GRB 240615A: GECAM detection
  74. X-ray transient EP240414a: Chandra late time observation
  75. GRB 240615A: FLWO-1.2m optical upper limits
  76. Fermi trigger No 740221779: Global MASTER-Net observations report
  77. Fermi GRB 240616A: Global MASTER-Net observations report
  78. Konus-Wind detection of GRB 240615A (short/hard)
  79. GRB 240615A: GOTO optical upper limits
  80. Fermi trigger No 740166710: Global MASTER-Net observations report
  81. GRB 240616A: Fermi GBM Final Real-time Localization
  82. GRB 240615A: Swift ToO observations
  83. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  84. GRB 240615A: Fermi GBM Final Real-time Localization
  85. LIGO/Virgo/KAGRA S240615ea: Identification of a GW compact binary merger candidate
  86. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  87. GRB 240603A: VZLUSAT-2 detection
  88. GRB 240612A: GRBAlpha detection
  89. GRB 240613A: Fermi GBM Final Real-time Localization
  90. Fermi GRB 240612B: Global MASTER-Net observations report
  91. Fermi GRB 240612A: Global MASTER-Net observations report
  92. GRB 240612B: Fermi GBM Final Real-time Localization
  93. GRB 240612A: Fermi GBM Final Real-time Localization
  94. GRB 240607A: GECAM detection of a bright long burst
  95. Fermi GRB 240611A: Global MASTER-Net observations report
  96. Konus-Wind detection of GRB 240607A
  97. GRB 240611A: Fermi GBM Final Real-time Localization
  98. EXO 0748-676: Swift-BAT refined analysis
  99. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  100. GRB 240529A: LBT optical detection and late temporal decay

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