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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"

27292 results found.

  1. GRB 230709B: GRBAlpha detection
  2. GRB 230709C: Fermi GBM Detection
  3. GRB 230709C: Fermi GBM Final Localization
  4. GRB 230707B: Fermi GBM Observation
  5. GRB 230710A: Fermi GBM Final Real-time Localization
  6. IceCube-230707A: No candidates detected by Swift-XRT
  7. Swift Trigger 1178410 is not an astrophysical event
  8. GRB 230709C: AstroSat CZTI detection
  9. GRB 230707B: CALET Gamma-Ray Burst Monitor detection
  10. Swift Trigger 1178410: possible GRB 230709A
  11. GRB 230628C: GRID Detection
  12. IceCube-230708A - IceCube observation of a high-energy neutrino candidate track-like event
  13. GRB 230707B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  14. GRB 230707A: Swift-XRT observations
  15. IceCube-230707B - IceCube observation of a high-energy neutrino candidate track-like event
  16. GRB 230707B: Fermi GBM Final Real-time Localization
  17. IceCube-230707A - IceCube observation of a high-energy neutrino candidate track-like event
  18. GRB 230707A: Fermi GBM Detection
  19. GRB 230707A: Swift ToO observations
  20. GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst
  21. GRB 230707A: Fermi GBM Final Real-time Localization
  22. IBAS trigger number 10311: not a real GRB
  23. GRB 230625A: Detection by GRID
  24. ZTF23aaoohpy/AT2023lcr: AMI-LA radio detection
  25. GRB 230626A: VZLUSAT-2 detection
  26. GRB 230328B: LBT detection of the likely host galaxy
  27. Konus-Wind detection of GRB 220623A
  28. GRB 230701B: AstroSat CZTI detection
  29. GRB 230628E: Swift/UVOT Detection
  30. GRB 230628E: Swift-BAT refined analysis
  31. GRB 230702A: Fermi GBM Final Real-time Localization
  32. GRB 230701A: Fermi GBM Final Real-time Localization
  33. LIGO/Virgo/KAGRA S230627c: Upper limits from Swift/BAT-GUANO
  34. IPN triangulation of GRB 230625B (ultra-long)
  35. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  36. GRB 230625B: CALET Gamma-Ray Burst Monitor detection
  37. GRB 230625B: AstroSat CZTI detection
  38. GRB230628E: VLT optical identification of afterglow candidate
  39. GRB 230628E: Swift-XRT refined Analysis
  40. GRB 230628E: Enhanced Swift-XRT position (Correction to name in GCN 34115)
  41. GRB 230628A: Enhanced Swift-XRT position
  42. GRB 230628E: LCOGT Optical Upper Limit
  43. Swift GRB230628.93: Global MASTER-Net observations report
  44. GRB 230628E: Swift detection of a burst
  45. GRB 230628D: Fermi GBM Final Real-time Localization
  46. GRB 230628C: Fermi GBM Final Real-time Localization
  47. GRB 230628B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  48. GRB 230623B: CALET Gamma-Ray Burst Monitor detection
  49. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  50. GRB 230628A: Fermi GBM Final Localization
  51. LIGO/Virgo/KAGRA S230627c: Additional observations from the Zwicky Transient Facility
  52. GRB 230626A: GRBAlpha detection
  53. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  54. GRB230626A: Fermi GBM Detection
  55. Konus-Wind detection of GRB 230616A
  56. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  57. GRB 230618A: Swift-BAT refined analysis
  58. GRB 230625B: Swift/BAT-GUANO detection of a long burst
  59. GRB 230622A: Swift-BAT refined analysis
  60. GRB 230623A: Swift-XRT observations
  61. GRB 230625A: Fermi GBM Final Real-time Localization
  62. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  63. GRB 230623B: Swift/BAT-GUANO detection of a long burst outside the coded FOV 
  64. GRB 230623A: Tiled Swift observations
  65. MAXI GRB 230623A: MASTER optical observations
  66. GRB 230623A: Tiled Swift observations
  67. GRB 230622A: Swift-XRT refined Analysis
  68. GRB 230623A: MAXI/GSC detection
  69. Swift GRB 230622A: Global MASTER-Net observations report
  70. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  71. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  72. GRB 230622A: Swift detection of a burst
  73. GRB 230621A: Fermi GBM Final Localization Correction
  74. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  75. AT2023lcr: VLA radio detection
  76. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  77. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  78. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  79. IPN triangulation of GRB 230616A (short)
  80. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  81. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  82. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  83. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  84. ZTF23aaoohpy/AT2023lcr: Zwicky Transient Facility discovery of a fast fading red transient
  85. LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates
  86. GRB 230618A: Enhanced Swift-XRT position
  87. GRB 230618A: Swift/UVOT Upper Limits
  88. GRB 230618A: Swift-XRT refined Analysis
  89. GRB 230616A: Swift-XRT observations
  90. GRB 230618A: KAIT Optical Observations
  91. Swift GRB 230618A: Global MASTER-Net observations report
  92. GRB230618A: LCOGT Optical Observations
  93. GRB 230618B: Fermi GBM Final Real-time Localization
  94. GRB 230618A: Prompt enhanced Swift-XRT position
  95. GRB 230618A: Swift detection of a burst
  96. GRB 230616A: Swift ToO observations
  97. GRB 230617A: Fermi GBM Final Real-time Localization
  98. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  99. GRB 230614C: GRBAlpha detection
  100. GRB 230616A: AstroSat CZTI detection

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