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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"

35958 results found.

  1. GRB 230330A: Fermi GBM Final Real-time Localization
  2. GRB 230328B: Swift-BAT refined analysis
  3. GRB 230328B: Nanshan/NEXT 2nd optical observation
  4. GRB 230328B NUTTelA-TAO / BSTI Early Measurements
  5. GRB 230328B: Liverpool Telescope afterglow detection
  6. GRB 230328B: OHP/T120 optical observations
  7. GRB 230328B: GIT optical follow-up
  8. GRB 230328B: OASDG optical observations
  9. GRB 230328B: Nanshan/NEXT optical upper limit
  10. GRB 230328B: Swift-XRT refined Analysis
  11. GRB 230328B: AstroSat CZTI detection
  12. GRB 230328B: Fermi GBM observation
  13. GRB 230328B: Mondy, AbAO and Kitab optical observations
  14. GRB 230328B: Enhanced Swift-XRT position
  15. GRB 230328B: Mondy optical afterglow confirmation
  16. GRB 230328B: Swift detection of a burst with an optical afterglow
  17. GRB 230328B: Fermi GBM Final Real-time Localization
  18. Fermi GRB 230328A: Global MASTER-Net observations report
  19. GRB 230328A: Fermi GBM Final Real-time Localization
  20. GRB 230325A: Swift-BAT refined analysis
  21. GRB 230325A: Swift/UVOT Upper Limits
  22. GRB 230325A: X-shooter optical afterglow and redshift
  23. GRB 230325A: Swift-XRT refined Analysis
  24. GRB 230322B: Swift-BAT refined analysis
  25. GRB 230325A: Enhanced Swift-XRT position
  26. GRB 230325A: Prompt enhanced Swift-XRT position
  27. GRB 230325A: Swift detection of a burst
  28. GRB 230320B: Fermi GBM Observation
  29. GRB 230322B: Swift/UVOT Detection
  30. Konus-Wind detection of GRB 230309A
  31. Konus-Wind detection of GRB 230308A
  32. Konus-Wind detection of GRB 230304B
  33. GRB 230322B: Swift-XRT refined Analysis
  34. GRB 230322B: Enhanced Swift-XRT position
  35. Swift GRB 230322B: Global MASTER-Net observations report
  36. GRB 230322B: Swift detection of a burst with optical counterpart
  37. GRB 230322A: Fermi GBM Final Real-time Localization
  38. GRB 230320B: GRBAlpha detection
  39. GRB 230321A: CALET Gamma-Ray Burst Monitor detection
  40. GRB 230320B: CALET Gamma-Ray Burst Monitor detection
  41. GRB 230320B: Swift/BAT-GUANO detection outside the coded FOV
  42. Fermi GRB 230320A: Global MASTER-Net observations report
  43. Fermi GRB 230321A: Global MASTER-Net observations report
  44. GRB 230321B: AstroSat CZTI detection
  45. GRB 230320B: AstroSat CZTI detection
  46. GRB 230321A: BALROG localization (Fermi Trigger 701065308 / GRB 230321182)
  47. GRB 230321A: Fermi GBM Final Real-time Localization
  48. GRB 230320A: Fermi GBM Final Real-time Localization
  49. GRB 230314A: TURBO Optical Upper Limit
  50. GRB 230307A: Continued Gemini-South observations confirm rapid optical fading
  51. IPN triangulation of GRB 230309A
  52. Fermi GRB 230316A: Global MASTER-Net observations report
  53. GRB 230304D: AstroSat CZTI detection
  54. GRB 230316A: Fermi GBM Final Real-time Localization
  55. IPN triangulation of GRB 230304B
  56. GRB 230313A: AstroSat CZTI detection
  57. GRB 230307A: Far off-axis NuSTAR detection of the GRB
  58. IPN triangulation of GRB 230308A (short/bright)
  59. Fermi GRB 230314A: Global MASTER-Net observations report
  60. GRB 230307A: ATCA radio detection
  61. GRB 230314A: Fermi GBM Final Real-time Localization
  62. VZLUSAT-2 detection of SGR 1806-20
  63. GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
  64. GRB 230307A: Swift/UVOT detection
  65. GRB 230313A: BALROG localization (Fermi Trigger 700400328 / GRB 230313485)
  66. Fermi GRB 230313A: Global MASTER-Net observations report
  67. GRB 230313A: Fermi GBM Final Real-time Localization
  68. GRB 230307A: soft X-ray detection with LEIA
  69. GRB 230307A: Swift-XRT afterglow detection
  70. GRB 230309A: AstroSat CZTI detection of a bright long GRB
  71. Further improved IPN localization for GRB 230307A
  72. GRB 230307A: SOAR/Goodman detection of the possible host galaxy
  73. GRB 230308A: CALET Gamma-Ray Burst Monitor detection
  74. GRB 230310A: AstroSat CZTI detection
  75. GRB 230307A: GECKO optical observations and detections of the afterglow
  76. GRB 230307A: MAXI/GSC upper limit
  77. GRB 230307A: Gemini-South Confirmation of the Optical Afterglow
  78. Fermi GRB 230310A: Global MASTER-Net observations report
  79. GRB 230310A: Fermi GBM Final Real-time Localization
  80. GRB 230307A: AGILE/MCAL analysis
  81. GRB 230307A: ATLAS information on the ULTRACAM optical afterglow candidate
  82. GRB 230307A: Erratum of the GCN 33441
  83. GRB 230204B: MASTER detection of an object near NTT Optical Afterglow Candidate
  84. GRB 230308A: Fermi GBM detection
  85. GRB 230307A: Possible optical afterglow
  86. GRB 230307A: ASO-S/HXI detection
  87. GRB 230307A: AstroSat LAXPC detection
  88. GRB 230228A: NUTTelA-TAO / BSTI Optical Limits
  89. GRB 230308A: AGILE/MCAL detection
  90. GRB 230307A: optical upper limit
  91. GRB 230217A: ATCA rapid-response radio detection
  92. Swift Trigger 1159108 is not a GRB
  93. GRB 230307A: Swift/BAT upper limits on the early afterglow
  94. GRB 230307A: Upper limits from a neutrino search with IceCube
  95. GRB 230307A: Swift-XRT observations
  96. Fermi GRB 230307A: Global MASTER-Net observations report
  97. Konus-Wind detection of GRB 230307A
  98. GRB 230228A: VIRT Optical Upper Limit
  99. Improved IPN localization for GRB 230307A
  100. GRB 230307A: VZLUSAT-2 detection

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