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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"

45790 results found.

  1. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  2. IPN triangulation of GRB 240627A
  3. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  4. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  5. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  6. EP240703b: EP-WXT detection of a fast X-ray transient
  7. Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
  8. EP240702a: Swift/XRT upper limit
  9. EP240703a: EP-WXT detection of a fast X-ray transient
  10. EP240702a: GSP optical upper limit
  11. The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
  12. GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
  13. Fermi GRB 240702A: Global MASTER-Net observations report
  14. GRB 240702A: Fermi GBM Final Real-time Localization
  15. EP240702a: EP-WXT detection of a fast X-ray transient
  16. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  17. Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
  18. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  19. Fermi trigger No 741448122: Global MASTER-Net observations report
  20. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  21. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  22. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  23. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  24. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  25. Fermi trigger No 741356809: Global MASTER-Net observations report
  26. Fermi GRB 240629A: Global MASTER-Net observations report
  27. Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
  28. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  29. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  30. GRB 240629A: Fermi GBM Final Real-time Localization
  31. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  32. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  33. Fermi trigger No 741296200: Global MASTER-Net observations report
  34. Fermi trigger No 741251380: Global MASTER-Net observations report
  35. IPN triangulation of GRB 240619C
  36. IceCube-Cascade 240626A: Upper limits from a search for additional neutrino events in IceCube
  37. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  38. GRB 240627A: NuSTAR Detection of the long GRB
  39. GRB 240615A: SAI CMO J- band observations
  40. GRB 240627A: AstroSat CZTI detection
  41. Fermi trigger No 741211696: Global MASTER-Net observations report
  42. EP240626a: Montarrenti Observatory optical upper limit
  43. EP240626a: KAIT optical upper limit
  44. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  45. EP240625a: GRANDMA Optical Upper Limits
  46. EP240626a: EP-FXT detection of the X-ray emission
  47. GRB 240624A: Swift-BAT refined analysis
  48. Konus-Wind detection of GRB 240619A
  49. EP240626a: BOOTES-7 optical upper limit
  50. EP240626a: EP-WXT detection of a fast X-ray transient
  51. Fermi GRB 240625B: Global MASTER-Net observations report
  52. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  53. GRB 240625B: Fermi GBM Final Real-time Localization
  54. GRB 240625A: Fermi GBM Observation
  55. EP240625a: NOT optical counterpart candidate
  56. EP240625a: EP-FXT detection of the X-ray emission
  57. GRB 240624B: GRBAlpha detection
  58. GRB 240625A: Fermi GBM Final Real-time Localization
  59. EP240625a: EP-WXT detection of a fast X-ray transient
  60. GRB240624A: Fermi GBM Observation
  61. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  62. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  63. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  64. Swift GRB 240624A: Global MASTER-Net observations report
  65. GRB240615A: Gemini-North observations of the BAT and XRT positions
  66. Fermi GRB 240624A: Global MASTER-Net observations report
  67. GRB 240624B: Fermi GBM Final Real-time Localization
  68. Fermi trigger No 740949590: Global MASTER-Net observations report
  69. LIGO/Virgo/KAGRA S240624cd: Retraction of GW unmodeled transient candidate
  70. GRB240615A: Gemini-North observations of the BAT and XRT positions
  71. GRB 240624A: Fermi GBM Final Real-time Localization
  72. GRB 240619A: detection of a radio counterpart with AMI-LA
  73. GRB 240624A: Swift detection of a burst
  74. LIGO/Virgo/KAGRA S240623dg: Retraction of GW compact binary merger candidate
  75. EP240618a: NOT further optical observations
  76. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  77. GRB 240619A: J-band detection with WINTER
  78. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  79. Fermi trigger No 740744838: Global MASTER-Net observations report
  80. EP240618a: NOT optical counterpart candidate
  81. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  82. GRB 240529A: JinShan optical observations
  83. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  84. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  85. EP240618a: GSP optical upper limit
  86. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  87. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  88. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  89. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  90. IPN triangulation of GRB 240615A (short)
  91. X-ray transient EP240618a: Fermi/GBM non-detection
  92. GRB 240619A: GRBAlpha detection
  93. EP240618a: Swift/XRT upper limit
  94. EP240617a: tentative Swift/XRT detection of the afterglow
  95. GRB 240619A: Swift-XRT probable afterglow detection
  96. GRB 240619A: Swift ToO observations
  97. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  98. GRB 240619C: NuSTAR automated detection of the GRB
  99. GRB 240619A: Fermi GBM Observation
  100. Fermi GBM Sub-Threshold Detection of GRB 240619C

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