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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"

32726 results found.

  1. EP240702a: Swift/XRT upper limit
  2. EP240702a: GSP optical upper limit
  3. Fermi GRB 240702A: Global MASTER-Net observations report
  4. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  5. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  6. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  7. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  8. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  9. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  10. Fermi GRB 240629A: Global MASTER-Net observations report
  11. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  12. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  13. IPN triangulation of GRB 240619C
  14. GRB 240627A: NuSTAR Detection of the long GRB
  15. GRB 240615A: SAI CMO J- band observations
  16. EP240626a: Montarrenti Observatory optical upper limit
  17. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  18. EP240625a: GRANDMA Optical Upper Limits
  19. EP240626a: EP-FXT detection of the X-ray emission
  20. GRB 240624A: Swift-BAT refined analysis
  21. Konus-Wind detection of GRB 240619A
  22. Fermi GRB 240625B: Global MASTER-Net observations report
  23. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  24. GRB 240625A: Fermi GBM Observation
  25. EP240625a: NOT optical counterpart candidate
  26. EP240625a: EP-FXT detection of the X-ray emission
  27. GRB 240624B: GRBAlpha detection
  28. GRB240624A: Fermi GBM Observation
  29. Swift GRB 240624A: Global MASTER-Net observations report
  30. GRB240615A: Gemini-North observations of the BAT and XRT positions
  31. Fermi GRB 240624A: Global MASTER-Net observations report
  32. GRB240615A: Gemini-North observations of the BAT and XRT positions
  33. GRB 240619A: detection of a radio counterpart with AMI-LA
  34. EP240618a: NOT further optical observations
  35. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  36. GRB 240619A: J-band detection with WINTER
  37. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  38. EP240618a: NOT optical counterpart candidate
  39. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  40. GRB 240529A: JinShan optical observations
  41. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  42. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  43. EP240618a: GSP optical upper limit
  44. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  45. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  46. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  47. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  48. IPN triangulation of GRB 240615A (short)
  49. X-ray transient EP240618a: Fermi/GBM non-detection
  50. GRB 240619A: GRBAlpha detection
  51. EP240618a: Swift/XRT upper limit
  52. EP240617a: tentative Swift/XRT detection of the afterglow
  53. GRB 240619A: Swift-XRT probable afterglow detection
  54. GRB 240619A: Swift ToO observations
  55. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  56. GRB 240619C: NuSTAR automated detection of the GRB
  57. GRB 240619A: Fermi GBM Observation
  58. Fermi GBM Sub-Threshold Detection of GRB 240619C
  59. GRB 240619A: GOTO candidate optical afterglow
  60. EP240618a: Abastumani optical observationsEP240618a
  61. GRB 240615A: NOT optical observations
  62. EP240618a: GRANDMA Optical Upper Limits
  63. EP240618a: TRT optical upper limit
  64. Fermi GRB 240619A: Global MASTER-Net observations report
  65. EP240617a: STEP/T80S optical limits
  66. GRB 240615A: possible transient detection from Wendelstein observations
  67. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  68. LIGO/Virgo/KAGRA S240615dg: Updated Sky localization
  69. LIGO/Virgo/KAGRA S240618ah: Updated Sky localization
  70. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  71. GRB240615A: 1.3m DFOT optical upper limit
  72. EP240617a is likely a GRB event
  73. LIGO/Virgo/KAGRA S240618ah: Identification of a GW compact binary merger candidate
  74. GRB 240615A: J-band upper limits from WINTER
  75. GRB 240615A: Fermi GBM Observation
  76. LIGO/Virgo/KAGRA S240615ea: Updated Sky localization
  77. GRB 240615A: GECAM detection
  78. X-ray transient EP240414a: Chandra late time observation
  79. GRB 240615A: FLWO-1.2m optical upper limits
  80. Fermi GRB 240616A: Global MASTER-Net observations report
  81. Konus-Wind detection of GRB 240615A (short/hard)
  82. GRB 240615A: GOTO optical upper limits
  83. GRB 240615A: Swift ToO observations
  84. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  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. Fermi GRB 240612B: Global MASTER-Net observations report
  90. Fermi GRB 240612A: Global MASTER-Net observations report
  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. EXO 0748-676: Swift-BAT refined analysis
  95. GRB 240529A: LBT optical detection and late temporal decay
  96. GRB 240529A : MITSuME Akeno optical afterglow detection
  97. Fermi GRB 240610A: Global MASTER-Net observations report
  98. IPN triangulation of GRB 240607A
  99. Fermi GRB 240608A: Global MASTER-Net observations report
  100. Konus-Wind detection of GRB 240606B

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