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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"

32761 results found.

  1. GRB 240713A: OHP/T120 optical upper limit
  2. GRB240713A: X-ray follow-up observation with EP-FXT (duplicate submission of GCN 36859)
  3. GRB240713A: X-ray follow-up observation with EP-FXT
  4. GRB240713A: Optical upper limit with Kinder observations
  5. Fermi Sub-threshold Observation of GRB240713A
  6. EP240708a: GSP optical upper limit
  7. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  8. EP240708a: KAIT optical upper limit
  9. Fermi GRB 240710A: Global MASTER-Net observations report
  10. EP240708a: NOT optical observations
  11. EP240708a: SVOM/C-GFT optical upper limit
  12. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  13. EP240708a: Optical upper limits with Kinder observations
  14. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  15. EP240703b: GSP optical upper limit
  16. EP240703b: TRT optical upper limits
  17. EP240703a: TRT further optical observation
  18. EP240702a: TRT optical upper limits
  19. Konus-Wind detection of GRB 240627A
  20. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  21. EP240703a and EP240703b: Swift/XRT upper limits
  22. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  23. EP240703a: KAIT optical upper limit
  24. EP240703a: BTA observations
  25. EP240703c: Kinder optical follow-up and Swift XRT observations
  26. EP240703a: Liverpool Telescope optical follow-up observations
  27. EP240703a/GRB 240703A: TRT optical candidate likely not real
  28. EP240703a: Kinder optical follow-up observations
  29. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  30. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  31. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  32. IPN triangulation of GRB 240627A
  33. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  34. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  35. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  36. Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
  37. EP240702a: Swift/XRT upper limit
  38. EP240702a: GSP optical upper limit
  39. Fermi GRB 240702A: Global MASTER-Net observations report
  40. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  41. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  42. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  43. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  44. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  45. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  46. Fermi GRB 240629A: Global MASTER-Net observations report
  47. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  48. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  49. IPN triangulation of GRB 240619C
  50. GRB 240627A: NuSTAR Detection of the long GRB
  51. GRB 240615A: SAI CMO J- band observations
  52. EP240626a: Montarrenti Observatory optical upper limit
  53. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  54. EP240625a: GRANDMA Optical Upper Limits
  55. EP240626a: EP-FXT detection of the X-ray emission
  56. GRB 240624A: Swift-BAT refined analysis
  57. Konus-Wind detection of GRB 240619A
  58. Fermi GRB 240625B: Global MASTER-Net observations report
  59. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  60. GRB 240625A: Fermi GBM Observation
  61. EP240625a: NOT optical counterpart candidate
  62. EP240625a: EP-FXT detection of the X-ray emission
  63. GRB 240624B: GRBAlpha detection
  64. GRB240624A: Fermi GBM Observation
  65. Swift GRB 240624A: Global MASTER-Net observations report
  66. GRB240615A: Gemini-North observations of the BAT and XRT positions
  67. Fermi GRB 240624A: Global MASTER-Net observations report
  68. GRB240615A: Gemini-North observations of the BAT and XRT positions
  69. GRB 240619A: detection of a radio counterpart with AMI-LA
  70. EP240618a: NOT further optical observations
  71. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  72. GRB 240619A: J-band detection with WINTER
  73. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  74. EP240618a: NOT optical counterpart candidate
  75. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  76. GRB 240529A: JinShan optical observations
  77. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  78. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  79. EP240618a: GSP optical upper limit
  80. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  81. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  82. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  83. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  84. IPN triangulation of GRB 240615A (short)
  85. X-ray transient EP240618a: Fermi/GBM non-detection
  86. GRB 240619A: GRBAlpha detection
  87. EP240618a: Swift/XRT upper limit
  88. EP240617a: tentative Swift/XRT detection of the afterglow
  89. GRB 240619A: Swift-XRT probable afterglow detection
  90. GRB 240619A: Swift ToO observations
  91. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  92. GRB 240619C: NuSTAR automated detection of the GRB
  93. GRB 240619A: Fermi GBM Observation
  94. Fermi GBM Sub-Threshold Detection of GRB 240619C
  95. GRB 240619A: GOTO candidate optical afterglow
  96. EP240618a: Abastumani optical observationsEP240618a
  97. GRB 240615A: NOT optical observations
  98. EP240618a: GRANDMA Optical Upper Limits
  99. EP240618a: TRT optical upper limit
  100. Fermi GRB 240619A: Global MASTER-Net observations report

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