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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

14824 results found.

  1. LIGO/Virgo/KAGRA S240623dg: Retraction of GW compact binary merger candidate
  2. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  3. GRB 240619A: J-band detection with WINTER
  4. EP240618a: GSP optical upper limit
  5. IPN triangulation of GRB 240615A (short)
  6. X-ray transient EP240618a: Fermi/GBM non-detection
  7. GRB 240619A: GRBAlpha detection
  8. EP240618a: Swift/XRT upper limit
  9. EP240617a: tentative Swift/XRT detection of the afterglow
  10. GRB 240619A: Swift-XRT probable afterglow detection
  11. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  12. GRB 240619C: NuSTAR automated detection of the GRB
  13. Fermi GBM Sub-Threshold Detection of GRB 240619C
  14. GRB 240619A: GOTO candidate optical afterglow
  15. GRB 240615A: NOT optical observations
  16. GRB 240619C: AstroSat CZTI detection
  17. GRB 240615A: possible transient detection from Wendelstein observations
  18. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  19. EP240618a: BOOTES-6/DPRT optical upper limit
  20. GRB 240619B: Fermi GBM Final Real-time Localization
  21. GRB 240619A: Fermi GBM Final Real-time Localization
  22. EP240617a: BOOTES-6/DPRT optical upper limit
  23. EP240617a is likely a GRB event
  24. EP240617a: EP-WXT detection of a fast X-ray transient
  25. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  26. GRB 240615A: GECAM detection
  27. Konus-Wind detection of GRB 240615A (short/hard)
  28. GRB 240616A: Fermi GBM Final Real-time Localization
  29. GRB 240615A: Fermi GBM Final Real-time Localization
  30. GRB 240603A: VZLUSAT-2 detection
  31. GRB 240612A: GRBAlpha detection
  32. GRB 240613A: Fermi GBM Final Real-time Localization
  33. GRB 240612B: Fermi GBM Final Real-time Localization
  34. GRB 240612A: Fermi GBM Final Real-time Localization
  35. GRB 240607A: GECAM detection of a bright long burst
  36. Konus-Wind detection of GRB 240607A
  37. GRB 240611A: Fermi GBM Final Real-time Localization
  38. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  39. GRB 240529A: LBT optical detection and late temporal decay
  40. GRB 240529A : MITSuME Akeno optical afterglow detection
  41. Trigger 1236151: Swift detection of EXO 0748-676
  42. GRB 240610A: Fermi GBM Final Real-time Localization
  43. IPN triangulation of GRB 240607A
  44. Konus-Wind detection of GRB 240606B
  45. GRB 240608A: Fermi GBM Final Real-time Localization
  46. GRB 240529A: NOEMA detection
  47. GRB 240607A: AstroSat CZTI detection of bright long burst
  48. GRB 240607A: Fermi GBM detection of a very bright burst
  49. GRB 240529A: radio detection with AMI-LA
  50. GRB 240607A: Fermi GBM Final Real-time Localization
  51. GRB 240606B: GECAM-B detection a long burst
  52. GRB 240606B: Swift-XRT afterglow detection
  53. Konus-Wind detection of GRB 240603A
  54. IPN triangulation of GRB 240531A (short)
  55. GRB 240605C: Fermi GBM Final Real-time Localization
  56. IPN triangulation of GRB 240603A
  57. GRB 240605B: Fermi GBM Final Real-time Localization
  58. GRB 240604A: Fermi GBM Final Localization
  59. GRB 240605A: Fermi GBM Final Real-time Localization
  60. GRB 240604A: GECAM detection of a long burst
  61. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  62. GRB 240603A: Fermi GBM Final Localization
  63. GRB 240603C: Fermi GBM Final Real-time Localization
  64. GRB 240603B: Swift detection of a possible burst
  65. GRB 240529A: MASTER prompt OT detection
  66. GRB 240603A: GECAM detection of a short burst
  67. GRB 240529A: OSN optical detection
  68. The EP-WXT source triggered on June 1st is likely a flaring star
  69. GRB 240602A: Fermi GBM Final Real-time Localization
  70. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  71. LXT 240528A: GSP optical upper limit
  72. GRB 240529A: 1.3m DFOT Optical observations
  73. GRB 240531A: AstroSat CZTI detection of a short burst
  74. Konus-Wind detection of GRB 240529A
  75. IPN triangulation of the initial episode of GRB 240529A
  76. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  77. GRB 240529A: Insight-HXMT/HE detection
  78. GRB 240529A: optical photometry from Konkoly
  79. GRB 240529A: GROWTH-India optical follow-up
  80. GRB 240529A: T193/MISTRAL observations
  81. GRB 240529A: AKO Optical Afterglow Detection
  82. LXT 240528A: LEIA detection of a fast X-ray transient
  83. GRB240529A: BOOTES-6/DPRT optical detection
  84. GRB 240529A: Swift/UVOT Detection
  85. GRB 240529A: AstroSat CZTI detection
  86. GRB 240529A: GOTO optical afterglow detection
  87. GRB 240527B: Swift-XRT afterglow detection
  88. GRB 240529A: Swift detection of a burst with an optical counterpart
  89. GRB 240527B: Fermi-LAT detection
  90. GRB 240527B: Fermi GBM Final Localization
  91. GRB 240527A: Fermi GBM Final Real-time Localization
  92. GRB 240523A: Swift detection of a burst
  93. Fermi GBM Sub-Threshold Detection of GRB 240516B
  94. GRB 240513A: Swift-XRT afterglow detection
  95. EP240518a: GSP optical upper limit
  96. GRB 240521A: GECAM-B detection of a long burst
  97. GRB 240516B: AstroSat CZTI detection
  98. GRB 240514B: VZLUSAT-2 detection
  99. GRB 240504A: VZLUSAT-2 detection
  100. GRB 240502A: VZLUSAT-2 detection

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