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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"

22046 results found.

  1. EP240626a: Montarrenti Observatory optical upper limit
  2. EP240625a: GRANDMA Optical Upper Limits
  3. Konus-Wind detection of GRB 240619A
  4. EP240626a: EP-WXT detection of a fast X-ray transient
  5. Fermi GRB 240625B: Global MASTER-Net observations report
  6. EP240625a: NOT optical counterpart candidate
  7. EP240625a: EP-WXT detection of a fast X-ray transient
  8. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  9. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  10. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  11. Swift GRB 240624A: Global MASTER-Net observations report
  12. GRB240615A: Gemini-North observations of the BAT and XRT positions
  13. Fermi GRB 240624A: Global MASTER-Net observations report
  14. Fermi trigger No 740949590: Global MASTER-Net observations report
  15. GRB240615A: Gemini-North observations of the BAT and XRT positions
  16. GRB 240619A: detection of a radio counterpart with AMI-LA
  17. EP240618a: NOT further optical observations
  18. GRB 240619A: J-band detection with WINTER
  19. Fermi trigger No 740744838: Global MASTER-Net observations report
  20. EP240618a: NOT optical counterpart candidate
  21. GRB 240529A: JinShan optical observations
  22. EP240618a: GSP optical upper limit
  23. EP240617a: tentative Swift/XRT detection of the afterglow
  24. GRB 240619A: Swift-XRT probable afterglow detection
  25. GRB 240619A: Swift ToO observations
  26. GRB 240619A: GOTO candidate optical afterglow
  27. EP240618a: Abastumani optical observationsEP240618a
  28. GRB 240615A: NOT optical observations
  29. EP240618a: GRANDMA Optical Upper Limits
  30. EP240618a: TRT optical upper limit
  31. Fermi trigger No 740474239: Global MASTER-Net observations report
  32. Fermi GRB 240619A: Global MASTER-Net observations report
  33. EP240617a: STEP/T80S optical limits
  34. GRB 240615A: possible transient detection from Wendelstein observations
  35. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  36. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  37. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  38. Fermi trigger No 740430582: Global MASTER-Net observations report
  39. EP240617a: EP-WXT detection of a fast X-ray transient
  40. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  41. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  42. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  43. GRB 240615A: J-band upper limits from WINTER
  44. GRB 240615A: Swift-XRT observations
  45. X-ray transient EP240414a: Chandra late time observation
  46. Fermi trigger No 740221779: Global MASTER-Net observations report
  47. Fermi GRB 240616A: Global MASTER-Net observations report
  48. GRB 240615A: GOTO optical upper limits
  49. Fermi trigger No 740166710: Global MASTER-Net observations report
  50. GRB 240615A: Swift ToO observations
  51. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  52. Fermi GRB 240612B: Global MASTER-Net observations report
  53. Fermi GRB 240612A: Global MASTER-Net observations report
  54. Fermi GRB 240611A: Global MASTER-Net observations report
  55. Konus-Wind detection of GRB 240607A
  56. GRB240529A: 3.6m TNG NIR detection 8d after the burst
  57. GRB 240529A: LBT optical detection and late temporal decay
  58. Trigger 1236151: Swift detection of EXO 0748-676
  59. Fermi GRB 240610A: Global MASTER-Net observations report
  60. Fermi trigger No 739632045: Global MASTER-Net observations report
  61. Fermi GRB 240608A: Global MASTER-Net observations report
  62. Konus-Wind detection of GRB 240606B
  63. Fermi trigger No 739506569: Global MASTER-Net observations report
  64. Fermi GRB 240607A: Global MASTER-Net observations report
  65. GRB 240529A: NOEMA detection
  66. GRB 240529A: radio detection with AMI-LA
  67. Fermi trigger No 739373591: Global MASTER-Net observations report
  68. GRB 240606B: Swift-XRT afterglow detection
  69. Swift GRB240606.15: Global MASTER-Net observations report
  70. GRB 240606B: Swift ToO observations
  71. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  72. Fermi GRB 240604A: Global MASTER-Net observations report
  73. Fermi GRB 240605A: Global MASTER-Net observations report
  74. Fermi GRB 240605C: Global MASTER-Net observations report
  75. GRB 240529A: SAO RAS optical observations
  76. Fermi GRB 240603C: Global MASTER-Net observations report
  77. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  78. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  79. GRB 240529A: MASTER prompt OT detection
  80. GRB 240529A: continued SAO RAS optical observations
  81. Fermi GRB 240602A: Global MASTER-Net observations report
  82. GRB 240529A: OSN optical detection
  83. GRB 240529A: further SAO RAS optical observations
  84. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  85. LXT 240528A: GSP optical upper limit
  86. GRB 240529A: 1.3m DFOT Optical observations
  87. GRB 240529A : Mondy optical observations
  88. Konus-Wind detection of GRB 240529A
  89. GRB 240529A: SAO RAS optical observations
  90. GRB 240529A: optical photometry from Konkoly
  91. GRB 240529A: T193/MISTRAL observations
  92. GRB 240529A: AKO Optical Afterglow Detection
  93. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  94. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  95. GRB 240529A: J-band detections with WINTER
  96. GRB 240529A: Skynet Optical Observations
  97. LXT 240528A: LEIA detection of a fast X-ray transient
  98. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  99. GRB 240529A: Swift/UVOT Detection
  100. GRB 240529A: NOT optical observations

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