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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"

27772 results found.

  1. GRB 230707A: Fermi GBM Final Real-time Localization
  2. IBAS trigger number 10311: not a real GRB
  3. GRB 230625A: Detection by GRID
  4. ZTF23aaoohpy/AT2023lcr: AMI-LA radio detection
  5. GRB 230626A: VZLUSAT-2 detection
  6. GRB 230328B: LBT detection of the likely host galaxy
  7. Konus-Wind detection of GRB 220623A
  8. GRB 230701B: AstroSat CZTI detection
  9. GRB 230628E: Swift/UVOT Detection
  10. GRB 230628E: Swift-BAT refined analysis
  11. GRB 230702A: Fermi GBM Final Real-time Localization
  12. GRB 230701A: Fermi GBM Final Real-time Localization
  13. LIGO/Virgo/KAGRA S230627c: Upper limits from Swift/BAT-GUANO
  14. IPN triangulation of GRB 230625B (ultra-long)
  15. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  16. GRB 230625B: CALET Gamma-Ray Burst Monitor detection
  17. GRB 230625B: AstroSat CZTI detection
  18. GRB230628E: VLT optical identification of afterglow candidate
  19. GRB 230628E: Swift-XRT refined Analysis
  20. GRB 230628E: Enhanced Swift-XRT position (Correction to name in GCN 34115)
  21. GRB 230628A: Enhanced Swift-XRT position
  22. GRB 230628E: LCOGT Optical Upper Limit
  23. Swift GRB230628.93: Global MASTER-Net observations report
  24. GRB 230628E: Swift detection of a burst
  25. GRB 230628D: Fermi GBM Final Real-time Localization
  26. GRB 230628C: Fermi GBM Final Real-time Localization
  27. GRB 230628B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  28. GRB 230623B: CALET Gamma-Ray Burst Monitor detection
  29. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  30. GRB 230628A: Fermi GBM Final Localization
  31. LIGO/Virgo/KAGRA S230627c: Additional observations from the Zwicky Transient Facility
  32. GRB 230626A: GRBAlpha detection
  33. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  34. GRB230626A: Fermi GBM Detection
  35. Konus-Wind detection of GRB 230616A
  36. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  37. GRB 230618A: Swift-BAT refined analysis
  38. GRB 230625B: Swift/BAT-GUANO detection of a long burst
  39. GRB 230622A: Swift-BAT refined analysis
  40. GRB 230623A: Swift-XRT observations
  41. GRB 230625A: Fermi GBM Final Real-time Localization
  42. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  43. GRB 230623B: Swift/BAT-GUANO detection of a long burst outside the coded FOV 
  44. GRB 230623A: Tiled Swift observations
  45. MAXI GRB 230623A: MASTER optical observations
  46. GRB 230623A: Tiled Swift observations
  47. GRB 230622A: Swift-XRT refined Analysis
  48. GRB 230623A: MAXI/GSC detection
  49. Swift GRB 230622A: Global MASTER-Net observations report
  50. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  51. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  52. GRB 230622A: Swift detection of a burst
  53. GRB 230621A: Fermi GBM Final Localization Correction
  54. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  55. AT2023lcr: VLA radio detection
  56. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  57. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  58. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  59. IPN triangulation of GRB 230616A (short)
  60. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  61. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  62. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  63. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  64. ZTF23aaoohpy/AT2023lcr: Zwicky Transient Facility discovery of a fast fading red transient
  65. LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates
  66. GRB 230618A: Enhanced Swift-XRT position
  67. GRB 230618A: Swift/UVOT Upper Limits
  68. GRB 230618A: Swift-XRT refined Analysis
  69. GRB 230616A: Swift-XRT observations
  70. GRB 230618A: KAIT Optical Observations
  71. Swift GRB 230618A: Global MASTER-Net observations report
  72. GRB230618A: LCOGT Optical Observations
  73. GRB 230618B: Fermi GBM Final Real-time Localization
  74. GRB 230618A: Prompt enhanced Swift-XRT position
  75. GRB 230618A: Swift detection of a burst
  76. GRB 230616A: Swift ToO observations
  77. GRB 230617A: Fermi GBM Final Real-time Localization
  78. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  79. GRB 230614C: GRBAlpha detection
  80. GRB 230616A: AstroSat CZTI detection
  81. GRB 230616A: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  82. GRB 230614C: AstroSat CZTI detection
  83. GRB 230614B: Fermi GBM Observation
  84. GRB 230614C: Fermi GBM Detection
  85. GRB 230614B: Swift/BAT-GUANO detection outside the coded FOV
  86. GRB 230614B: Fermi GBM Final Real-time Localization
  87. GRB 230614A: Fermi GBM Final Real-time Localization
  88. GRB 230606A: LCOGT Optical Observations
  89. GRB 230608A: CALET Gamma-Ray Burst Monitor detection
  90. GRB 230608A: AstroSat CZTI detection
  91. GRB 230608A: AGILE detection
  92. ZTF and GIT Observations of the Candidate Optical Afterglow AT2023jxk
  93. GRB 230606A: Swift-BAT refined analysis
  94. GRB 230606A: Gaoyazi/GOT optical upper limit
  95. GRB 230606A: Fermi GBM Observation
  96. GRB 230606A: BOOTES-5/JGT optical upper limit
  97. LIGO/Virgo/KAGRA S230602ap: Zwicky Transient Facility observations
  98. GRB 230606A: Swift-XRT refined Analysis
  99. GRB 230604A: GRBAlpha detection
  100. GRB 230606A: Swift/UVOT Upper Limits

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