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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"

37549 results found.

  1. IPN triangulation of GRB 240810A (short)
  2. GRB 240811A: Swift-BAT refined analysis
  3. GRB 240809A: Swift-BAT refined analysis
  4. GRB 240812B: AstroSat CZTI detection of a long burst
  5. GRB 240811A: Bassano Bresciano Observatory upper limit
  6. GRB 240811A: Swift-XRT refined Analysis
  7. Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
  8. GRB 240811A: Swift/UVOT Upper Limits
  9. EP240801a: Assy-Turgen optical observations
  10. Fermi GRB 240810A: Global MASTER-Net observations report
  11. Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
  12. GRB 240812A: Fermi GBM Final Real-time Localization
  13. GRB 240811A: LCOGT Optical Upper Limit
  14. GRB 240811A: Enhanced Swift-XRT position
  15. GRB 240811A: Upper limits with Mephisto
  16. Konus-Wind detection of GRB 240809A
  17. Fermi trigger No 745057312: Global MASTER-Net observations report
  18. Swift GRB 240811A: Global MASTER-Net observations report
  19. GRB 240811A: Swift detection of a burst
  20. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  21. GRB 240810A: Fermi GBM Final Real-time Localization
  22. GRB 240809A: REM detection of the optical afterglow
  23. GRB 240809A: Bassano Bresciano Observatory optical observations
  24. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  25. GRB 240809A: Conclusive redshift from VLT
  26. Fermi-LAT gamma-ray observations of IceCube-240808A
  27. GRB 240809A: KAIT optical observations
  28. GRB 240808A: AstroSat CZTI detection
  29. GRB 240809A: GIT afterglow observations
  30. GRB 240809B: MAXI/GSC detection
  31. GRB 240809A: Swift/UVOT Detection
  32. GRB 240809A: Tentative redshift from NOT
  33. GRB 240809A: Swift-XRT refined Analysis
  34. IPN triangulation of GRB 240807A / EP 240807a
  35. Swift GRB 240809A: Global MASTER-Net observations report
  36. GRB 240809A: JinShan optical observations
  37. GRB 240809A: Enhanced Swift-XRT position
  38. GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations
  39. GRB 240809A: SVOM/GRM observation
  40. GRB 240808A: SVOM/GRM observation
  41. GRB 240807A: SVOM/GRM observation
  42. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  43. EP-WXT trigger 01709018832: SVOM/C-GFT observations of the star flare
  44. EP240807a: STEP/T80S optical limits
  45. GRB 240807B: AstroSat CZTI detection of a short burst
  46. IceCube-240808A - IceCube observation of a high-energy neutrino candidate track-like event
  47. GRB 240801A: GRBAlpha detection
  48. GRB 240807B: Fermi GBM Final Localization
  49. GRB 240710B: VZLUSAT-2 detection
  50. GRB 240805A: ATCA Radio Upper Limits
  51. Fermi trigger No 744761058: Global MASTER-Net observations report
  52. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  53. EP-WXT trigger 01709018832: KAIT optical observations of the star flare
  54. EP240802a/GRB240802A: KAIT optical upper limit
  55. GRB 240720B: VZLUSAT-2 detection
  56. GRB 240710A: VZLUSAT-2 detection
  57. GRB 240807A: Fermi GBM Final Localization
  58. GRB 240805B: GIT optical upper limit
  59. EP240806a: KAIT optical observations
  60. GRB 240805B: Swift-BAT refined analysis
  61. GRB 240805A: Swift-BAT refined analysis
  62. Fermi trigger No 744629911: Global MASTER-Net observations report
  63. EP240804a (GRB 240804B): NOT optical observations
  64. Konus-Wind detection of GRB 240802A (EP240802a)
  65. Improved IPN triangulation of GRB 240802A / EP 240802a
  66. Konus-Wind detection of GRB 240805A
  67. GRB 240805B Bassano Bresciano Observatory upper limit
  68. GRB240805A: Fermi GBM Observation
  69. GRB 240805B: JinShan optical afterglow detection
  70. GRB 240804B/EP240804a: Correction to the GRB name in GCN 37071
  71. GRB 240805B: AbAO, CrAO, and Terskol optical upper limits
  72. Konus-Wind detection of GRB 240804B (a counterpart of EP240804a)
  73. Fermi Gamma-ray Burst Monitor trigger 240806402/744629911 is not a GRB
  74. GRB 240626B: VZLUSAT-2 detection
  75. GRB 240624B: VZLUSAT-2 detection
  76. GRB 240619C: VZLUSAT-2 detection
  77. EP 240806A: LCO optical observations
  78. GRB 240805B: Optical detection with 1.6m Mephisto
  79. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  80. GRB 240805B: Swift-XRT refined Analysis
  81. Fermi trigger No 744544656: Global MASTER-Net observations report
  82. GRB 240805B: Swift/UVOT Upper Limits
  83. GRB 240805A: Swift/UVOT Upper Limits
  84. GRB 240805B: BTA optical afterglow candidate
  85. GRB 240805A: SVOM/GRM observation
  86. GRB 240805B: Enhanced Swift-XRT position
  87. GRB 240805B: LCOGT Optical Upper Limits
  88. Swift GRB 240805B: Global MASTER-Net observations report
  89. GRB 240805B: JinShan optical upper limits
  90. Fermi GRB 240805A: Global MASTER-Net observations report
  91. Swift GRB 240805A: Global MASTER-Net observations report
  92. Fermi Gamma-ray Burst Monitor trigger 744558410/240805574 is not a GRB
  93. GRB 240805A: Swift-XRT refined Analysis
  94. GRB 240805B: Swift detection of a burst
  95. GRB 240805A: Fermi-LAT detection
  96. GRB 240805A: INTEGRAL spectral analysis
  97. EP240801a: Continued optical observations at ZTSh (CraO)
  98. GRB 240805A: A long GRB detected by INTEGRAL
  99. GRB 240805A: Swift detection of a burst
  100. GRB 240805A: Fermi GBM Final Real-time Localization

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