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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"

45718 results found.

  1. GRB240615A: Gemini-North observations of the BAT and XRT positions
  2. Fermi GRB 240624A: Global MASTER-Net observations report
  3. GRB 240624B: Fermi GBM Final Real-time Localization
  4. Fermi trigger No 740949590: Global MASTER-Net observations report
  5. LIGO/Virgo/KAGRA S240624cd: Retraction of GW unmodeled transient candidate
  6. GRB240615A: Gemini-North observations of the BAT and XRT positions
  7. GRB 240624A: Fermi GBM Final Real-time Localization
  8. GRB 240619A: detection of a radio counterpart with AMI-LA
  9. GRB 240624A: Swift detection of a burst
  10. LIGO/Virgo/KAGRA S240623dg: Retraction of GW compact binary merger candidate
  11. EP240618a: NOT further optical observations
  12. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  13. GRB 240619A: J-band detection with WINTER
  14. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  15. Fermi trigger No 740744838: Global MASTER-Net observations report
  16. EP240618a: NOT optical counterpart candidate
  17. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  18. GRB 240529A: JinShan optical observations
  19. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  20. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  21. EP240618a: GSP optical upper limit
  22. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  23. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  25. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  26. IPN triangulation of GRB 240615A (short)
  27. X-ray transient EP240618a: Fermi/GBM non-detection
  28. GRB 240619A: GRBAlpha detection
  29. EP240618a: Swift/XRT upper limit
  30. EP240617a: tentative Swift/XRT detection of the afterglow
  31. GRB 240619A: Swift-XRT probable afterglow detection
  32. GRB 240619A: Swift ToO observations
  33. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  34. GRB 240619C: NuSTAR automated detection of the GRB
  35. GRB 240619A: Fermi GBM Observation
  36. Fermi GBM Sub-Threshold Detection of GRB 240619C
  37. GRB 240619A: GOTO candidate optical afterglow
  38. EP240618a: Abastumani optical observationsEP240618a
  39. GRB 240615A: NOT optical observations
  40. EP240618a: GRANDMA Optical Upper Limits
  41. GRB 240619C: AstroSat CZTI detection
  42. EP240618a: TRT optical upper limit
  43. Fermi trigger No 740474239: Global MASTER-Net observations report
  44. Fermi GRB 240619A: Global MASTER-Net observations report
  45. EP240617a: STEP/T80S optical limits
  46. GRB 240615A: possible transient detection from Wendelstein observations
  47. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  48. LIGO/Virgo/KAGRA S240615dg: Updated Sky localization
  49. LIGO/Virgo/KAGRA S240618ah: Updated Sky localization
  50. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  51. EP240618a: BOOTES-6/DPRT optical upper limit
  52. Fermi Gamma-ray Burst Monitor trigger 740474239/240619304 is not a GRB
  53. GRB 240619B: Fermi GBM Final Real-time Localization
  54. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  55. Fermi trigger No 740430582: Global MASTER-Net observations report
  56. GRB240615A: 1.3m DFOT optical upper limit
  57. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  58. GRB 240619A: Fermi GBM Final Real-time Localization
  59. EP240617a: BOOTES-6/DPRT optical upper limit
  60. EP240617a is likely a GRB event
  61. EP240617a: EP-WXT detection of a fast X-ray transient
  62. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  63. LIGO/Virgo/KAGRA S240618ah: Identification of a GW compact binary merger candidate
  64. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  65. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  66. GRB 240615A: J-band upper limits from WINTER
  67. GRB 240615A: Fermi GBM Observation
  68. LIGO/Virgo/KAGRA S240615ea: Updated Sky localization
  69. GRB 240615A: Swift-XRT observations
  70. GRB 240615A: GECAM detection
  71. X-ray transient EP240414a: Chandra late time observation
  72. GRB 240615A: FLWO-1.2m optical upper limits
  73. Fermi trigger No 740221779: Global MASTER-Net observations report
  74. Fermi GRB 240616A: Global MASTER-Net observations report
  75. Konus-Wind detection of GRB 240615A (short/hard)
  76. GRB 240615A: GOTO optical upper limits
  77. Fermi trigger No 740166710: Global MASTER-Net observations report
  78. GRB 240616A: Fermi GBM Final Real-time Localization
  79. GRB 240615A: Swift ToO observations
  80. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  81. GRB 240615A: Fermi GBM Final Real-time Localization
  82. LIGO/Virgo/KAGRA S240615ea: Identification of a GW compact binary merger candidate
  83. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  84. GRB 240603A: VZLUSAT-2 detection
  85. GRB 240612A: GRBAlpha detection
  86. GRB 240613A: Fermi GBM Final Real-time Localization
  87. Fermi GRB 240612B: Global MASTER-Net observations report
  88. Fermi GRB 240612A: Global MASTER-Net observations report
  89. GRB 240612B: Fermi GBM Final Real-time Localization
  90. GRB 240612A: Fermi GBM Final Real-time Localization
  91. GRB 240607A: GECAM detection of a bright long burst
  92. Fermi GRB 240611A: Global MASTER-Net observations report
  93. Konus-Wind detection of GRB 240607A
  94. GRB 240611A: Fermi GBM Final Real-time Localization
  95. EXO 0748-676: Swift-BAT refined analysis
  96. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  97. GRB 240529A: LBT optical detection and late temporal decay
  98. GRB 240529A : MITSuME Akeno optical afterglow detection
  99. Trigger 1236151: Swift detection of EXO 0748-676
  100. Fermi GRB 240610A: Global MASTER-Net observations report

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