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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"

24539 results found.

  1. LIGO/Virgo/KAGRA S231129ac: Identification of a GW compact binary merger candidate
  2. GRB 231129A: GECAM-C detection of a long burst
  3. GRB 231129A: INTEGRAL detection of a long GRB
  4. GRB 231129A: Swift detection of a burst
  5. LIGO/Virgo/KAGRA S231127cg: Updated Sky localization
  6. GRB 231128A: Fermi GBM Final Real-time Localization
  7. GRB 231123C: Fermi GBM Observation
  8. GRB 231123B: Fermi GBM Observation
  9. IceCube-231125A: Upper limits from a search for additional neutrino events in IceCube
  10. LIGO/Virgo/KAGRA S231127cg: Identification of a GW compact binary merger candidate
  11. GRB 231125A: GRBAlpha detection
  12. GRB 231125A: CALET Gamma-Ray Burst Monitor detection
  13. GRB 231125A (short): Glowbug gamma-ray detection
  14. GRB 231123B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  15. Update of IceCube-231125A - Corrected errors
  16. GRB 231124A: GRBAlpha detection
  17. IceCube-231125A - IceCube observation of a high-energy neutrino candidate track-like event
  18. Fermi trigger No 722653947: Global MASTER-Net observations report
  19. GRB 231126A: Fermi GBM Final Real-time Localization
  20. Fermi trigger No 722460326: Global MASTER-Net observations report
  21. Fermi trigger No 722507896: Global MASTER-Net observations report
  22. GRB 231123C: Swift/BAT-GUANO detection of a short burst likely outside the coded FOV
  23. Fermi trigger No 722462310: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S231118an: Updated Sky localization and EM Bright Classification
  25. GRB 231124A: CALET Gamma-Ray Burst Monitor detection
  26. GRB 231124A: Fermi GBM Final Real-time Localization
  27. GRB 231123C: Fermi GBM Final Real-time Localization
  28. GRB 231123B: Fermi GBM Final Real-time Localization
  29. Fermi trigger No 722400249: Global MASTER-Net observations report
  30. LIGO/Virgo/KAGRA S231123cg: Identification of a GW compact binary merger candidate
  31. GRB 231118A: REM optical afterglow detection
  32. GRB 231122B: AstroSat CZTI detection
  33. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  34. GRB 231117A: Chandra afterglow detection
  35. GRB 231123A: Fermi GBM Final Real-time Localization
  36. Fermi trigger No 722349867: Global MASTER-Net observations report
  37. GRB 231122A: GECAM detection
  38. GRB 231122B: GECAM detection
  39. GRB 231122A: Fermi GBM Final Real-time Localization
  40. GRB 231117A: Swift/UVOT late time observations
  41. GRB 231117A: Swift-BAT refined analysis
  42. GRB 231118A: GRBAlpha detection
  43. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  45. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  46. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  47. LIGO/Virgo/KAGRA S231119u: Updated Sky localization and Source Classification
  48. LIGO/Virgo/KAGRA S231118ab: Updated Sky localization and Source Classification
  49. LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
  50. GRB 231118A: VZLUSAT-2 detection
  51. GRB 231118A: Swift-BAT refined analysis
  52. Konus-Wind detection of GRB 231020A
  53. GRB 231118B: CALET Gamma-Ray Burst Monitor detection
  54. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  55. GRB 231118B: Fermi GBM observation
  56. GRB 231118A: Fermi GBM observation
  57. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  58. GRB 231120A: Fermi GBM Final Real-time Localization
  59. LIGO/Virgo/KAGRA S231119u: One counterpart neutrino candidate from IceCube neutrino searches
  60. GRB 231118A: VLT/X-shooter redshift
  61. Fermi trigger No 722039659: Global MASTER-Net observations report
  62. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  63. GRB 231117A: GECAM-C detection
  64. GRB 231115A: Upper limit from CALET Gamma-Ray Burst Monitor
  65. GRB 231117A: 10 GHz VLA detection
  66. GRB 231118B: BALROG localization (Fermi Trigger 722039659 / GRB 231118940)
  67. GRB 231118B: Fermi GBM Final Real-time Localization
  68. GRB 231118A: LCOGT Optical Observations
  69. Swift GRB231118.72: Global MASTER-Net observations report
  70. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  71. GRB 231118A: Skynet Optical Afterglow Discovery
  72. GRB 231118A: Fermi GBM Final Real-time Localization
  73. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  74. GRB 231117A: GRBAlpha detection
  75. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  76. GRB 231115A: Wendelstein Optical/Infrared Observations
  77. GRB 231115A: JinShan optical upper limits
  78. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  79. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  80. GRB 231117A: REM optical and NIR early-time observations
  81. GRB231117A: AGILE/MCAL analysis
  82. GRB 231117A: AKO Optical Upper Limit
  83. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  84. Swift GRB 231117A: Global MASTER-Net observations report
  85. GRB 231117A: ATLAS non-detection of an optical counterpart
  86. Konus-Wind detection of GRB 231117A (short/hard)
  87. GRB 231115A : OHP/T120 optical upper limit
  88. GRB 231117A : MITSuME Akeno optical upper limits
  89. GRB 231117A: Swift detection of a bright short burst
  90. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  91. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  92. Fermi GRB 231116A: Global MASTER-Net observations report
  93. Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
  94. GRB 231115A: AGILE/MCAL upper limits
  95. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  96. GRB 231116A: Fermi GBM Final Real-time Localization
  97. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  98. GRB 231115A: archival Chandra X-ray observations
  99. GRB 231115A: Upper limits from a neutrino search with IceCube
  100. GRB 231115A: Kinder observations with Lulin observatory

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