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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"

28248 results found.

  1. GRB231104A: LCOGT Optical Upper Limits
  2. GRB 231104A: Swift detection of a bright burst
  3. GRB 231104A: Fermi GBM Final Real-time Localization
  4. GRB 231103A: Fermi GBM Final Real-time Localization
  5. IceCube-231103A - IceCube observation of a high-energy neutrino candidate track-like event
  6. GRB 231101A: Glowbug gamma-ray detection
  7. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  8. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  9. GRB 231101A: Fermi GBM Final Real-time Localization
  10. GRB 231030B: GRBAlpha detection
  11. GRB 231028B: VZLUSAT-2 detection
  12. GRB 231030B: Fermi GBM Detection
  13. GRB 231030B: AstroSat CZTI detection
  14. IPN triangulation of GRB 231020A
  15. GRB 231030B: Fermi GBM Final Real-time Localization
  16. LIGO/Virgo/KAGRA S231030av: Retraction of GW compact binary merger candidate
  17. GRB 231024A: AKO Optical Counterpart Candidate
  18. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  19. GRB 231030A: Fermi GBM Final Real-time Localization
  20. GRID detection of GRB 231020A
  21. GRB 231028A: AstroSat CZTI detection
  22. GRB 231028A: Glowbug gamma-ray detection
  23. GRB 231028A: Fermi GBM Detection
  24. GRB 231028A: Swift detection of a burst
  25. GRB 231028A: Fermi GBM Final Real-time Localization
  26. IceCube-231027A - IceCube observation of a high-energy neutrino candidate track-like event
  27. GRB 231019A: Glowbug gamma-ray detection
  28. GRB 231024A: Fermi GBM Observation
  29. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  30. GRB 231025A: Fermi GBM Final Localization
  31. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  32. GRB 231020A: AstroSat CZTI detection
  33. GRB 231020B: AstroSat CZTI detection
  34. GRB 231024A: Fermi GBM Final Localization
  35. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  36. GRB 231020A: Fermi GBM Detection
  37. GRID detection of GRB 231004A
  38. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  39. GRB 231019A: VZLUSAT-2 detection
  40. GRB 231018A: VZLUSAT-2 detection
  41. GRB 231020B: Fermi GBM Final Real-time Localization
  42. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  43. GRB 231015A: NuSTAR Detection of Prompt Emission
  44. GRB 231020A: Fermi GBM Final Real-time Localization
  45. GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  46. GRB 231017A: 1.3m DFOT Optical upper limit
  47. GRB 231018A: GRBAlpha detection
  48. GRB 231018A: CALET Gamma-Ray Burst Monitor detection
  49. GRB 231018A: Glowbug gamma-ray detection
  50. Konus-Wind detection of GRB 231018A
  51. IPN triangulation of GRB 231018A
  52. GRB 231017A: Swift/UVOT Upper Limit
  53. GRB 230911C: ATCA detection of possible radio counterpart
  54. GRB 231019A: Fermi GBM Final Real-time Localization
  55. GRB 231017A: GOTO optical upper limits
  56. GRB 231017A: JinShan optical upper limit
  57. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  58. GRB 231017A: Las Cumbres optical upper limit
  59. GRB 231015A: Glowbug gamma-ray detection
  60. GRB 231017A: LCOGT Optical Upper Limits
  61. GRB231017A: GROWTH-India upper limits on the optical afterglow
  62. GRB 231015A: AstroSat CZTI detection
  63. GRB 231018A: Fermi GBM Detection
  64. GRB 231017A: Fermi GBM Detection
  65. GRB 231017A: Swift-XRT observations
  66. GRB 231018A: Fermi GBM Final Real-time Localization
  67. GRB 231017A: Swift ToO observations
  68. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  69. GRB231017A: Fermi GBM Final Localization
  70. (correction) Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field
  71. Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field.
  72. IceCube-231014A - IceCube observation of a high-energy neutrino candidate track-like event
  73. GRB 231012A: Fermi GBM Final Real-time Localization
  74. GRB 231012A: Fermi GBM Final Real-time Localization
  75. GRB 231004A: Glowbug gamma-ray detection
  76. IceCube-231004A: No significant detection in HAWC
  77. GRB 231004A: CALET Gamma-Ray Burst Monitor detection
  78. IceCube-231004A - IceCube observation of a high-energy neutrino candidate track-like event
  79. transient AT2023sva: radio observations with AMI-LA
  80. GRB 231004A: Fermi GBM Final Real-time Localization
  81. GRB 231003A: Fermi GBM Final Real-time Localization
  82. GRB 230827B: 10.4m GTC spectroscopic redshift
  83. GRB 230930A: Fermi GBM Final Real-time Localization
  84. NuEm-230927A: Swift-XRT follow-up
  85. AT2023sva / GRB230916B: GIT observations of the afterglow
  86. Konus-Wind detection of GRB 230919A
  87. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  88. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  89. GRB 230921A: Fermi GBM Final Real-time Localization
  90. GRB 230918B: VLT/X-shooter classification of AT 2023tbf (GOTO23aky) as a dwarf nova
  91. IPN triangulation of GRB 230919A (short)
  92. Correction to Fermi GBM Statement for Trigger 716527670/230916144
  93. Fermi GBM Statement for Trigger 716527670/230916144
  94. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  95. GRB 230919A: AstroSat CZTI detection
  96. AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
  97. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  98. GRB 230919A: Fermi GBM Final Real-time Localization
  99. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  100. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT

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