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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"

45716 results found.

  1. GRB 240711A: Fermi GBM Final Real-time Localization
  2. Fermi trigger No 742405878: Global MASTER-Net observations report
  3. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  4. Fermi trigger No 742317942: Global MASTER-Net observations report
  5. EP240708a: KAIT optical upper limit
  6. Fermi GRB 240710A: Global MASTER-Net observations report
  7. GRB 240710A: Fermi GBM Final Real-time Localization
  8. EP240708a: NOT optical observations
  9. EP240708a: SVOM/C-GFT optical upper limit
  10. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  11. EP240708a: Optical upper limits with Kinder observations
  12. EP240708a: EP-WXT detection of a fast X-ray transient
  13. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  14. EP240703b: GSP optical upper limit
  15. Fermi Gamma-ray Burst Monitor trigger 741911057/240705933 is not a GRB
  16. GRB 240705A: Fermi GBM Final Real-time Localization
  17. EP240703b: TRT optical upper limits
  18. EP240703a: TRT further optical observation
  19. EP240702a: TRT optical upper limits
  20. Konus-Wind detection of GRB 240627A
  21. IPN triangulation of GRB 240628B (short)
  22. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  23. EP240703a and EP240703b: Swift/XRT upper limits
  24. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  25. EP240703a: KAIT optical upper limit
  26. EP240703a: BTA observations
  27. EP240703c: Kinder optical follow-up and Swift XRT observations
  28. EP240703a: BOOTES-3 optical upper limit
  29. EP240703a: Liverpool Telescope optical follow-up observations
  30. EP240703a/GRB 240703A: TRT optical candidate likely not real
  31. EP240703a: Kinder optical follow-up observations
  32. EP240703c: EP-WXT detection of an X-ray transient
  33. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  34. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  35. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  36. IPN triangulation of GRB 240627A
  37. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  38. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  39. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  40. EP240703b: EP-WXT detection of a fast X-ray transient
  41. Konus-Wind detection of GRB 240703A (a counterpart of EP240703a)
  42. EP240702a: Swift/XRT upper limit
  43. EP240703a: EP-WXT detection of a fast X-ray transient
  44. EP240702a: GSP optical upper limit
  45. The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
  46. GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
  47. Fermi GRB 240702A: Global MASTER-Net observations report
  48. GRB 240702A: Fermi GBM Final Real-time Localization
  49. EP240702a: EP-WXT detection of a fast X-ray transient
  50. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  51. Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
  52. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  53. Fermi trigger No 741448122: Global MASTER-Net observations report
  54. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  55. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  56. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  57. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  58. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  59. Fermi trigger No 741356809: Global MASTER-Net observations report
  60. Fermi GRB 240629A: Global MASTER-Net observations report
  61. Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
  62. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  63. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  64. GRB 240629A: Fermi GBM Final Real-time Localization
  65. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  66. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  67. Fermi trigger No 741296200: Global MASTER-Net observations report
  68. Fermi trigger No 741251380: Global MASTER-Net observations report
  69. IPN triangulation of GRB 240619C
  70. IceCube-Cascade 240626A: Upper limits from a search for additional neutrino events in IceCube
  71. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  72. GRB 240627A: NuSTAR Detection of the long GRB
  73. GRB 240615A: SAI CMO J- band observations
  74. GRB 240627A: AstroSat CZTI detection
  75. Fermi trigger No 741211696: Global MASTER-Net observations report
  76. EP240626a: Montarrenti Observatory optical upper limit
  77. EP240626a: KAIT optical upper limit
  78. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  79. EP240625a: GRANDMA Optical Upper Limits
  80. EP240626a: EP-FXT detection of the X-ray emission
  81. GRB 240624A: Swift-BAT refined analysis
  82. Konus-Wind detection of GRB 240619A
  83. EP240626a: BOOTES-7 optical upper limit
  84. EP240626a: EP-WXT detection of a fast X-ray transient
  85. Fermi GRB 240625B: Global MASTER-Net observations report
  86. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  87. GRB 240625B: Fermi GBM Final Real-time Localization
  88. GRB 240625A: Fermi GBM Observation
  89. EP240625a: NOT optical counterpart candidate
  90. EP240625a: EP-FXT detection of the X-ray emission
  91. GRB 240624B: GRBAlpha detection
  92. GRB 240625A: Fermi GBM Final Real-time Localization
  93. EP240625a: EP-WXT detection of a fast X-ray transient
  94. GRB240624A: Fermi GBM Observation
  95. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  96. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  97. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  98. Swift GRB 240624A: Global MASTER-Net observations report
  99. GRB240615A: Gemini-North observations of the BAT and XRT positions
  100. Fermi GRB 240624A: Global MASTER-Net observations report

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