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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"

39367 results found.

  1. GRB 231017A: JinShan optical upper limit
  2. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  3. GRB 231017A: Las Cumbres optical upper limit
  4. GRB 231015A: Glowbug gamma-ray detection
  5. GRB 231017A: LCOGT Optical Upper Limits
  6. GRB231017A: GROWTH-India upper limits on the optical afterglow
  7. GRB 231015A: AstroSat CZTI detection
  8. GRB 231018A: Fermi GBM Detection
  9. GRB 231017A: Fermi GBM Detection
  10. GRB 231017A: Swift-XRT observations
  11. GRB 231012B may not be a GRB
  12. GRB 231018A: BALROG localization (Fermi Trigger / GRB 231018521)
  13. GRB 231018A: Fermi GBM Final Real-time Localization
  14. GRB 231017A: Swift ToO observations
  15. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  16. GRB231017A: Fermi GBM Final Localization
  17. LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
  18. (correction) Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field
  19. Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field.
  20. IceCube-231014A - IceCube observation of a high-energy neutrino candidate track-like event
  21. Correction in GCN 34814: GRB 231012B (not GRB 231012A)
  22. GRB 231012A: Fermi GBM Final Real-time Localization
  23. GRB 231012A: Fermi GBM Final Real-time Localization
  24. GRB 231004A: Glowbug gamma-ray detection
  25. LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO
  26. GRB 231004A: CALET Gamma-Ray Burst Monitor detection
  27. Fermi-LAT gamma-ray observations of IceCube-231004A
  28. GRB 231004A: Fermi GBM Final Real-time Localization
  29. GRB 231003A is not a GRB
  30. GRB 231003A: Fermi GBM Final Real-time Localization
  31. LIGO/Virgo/KAGRA S231001aq: Upper limits from Swift/BAT-GUANO
  32. LIGO/Virgo/KAGRA S230930al: Upper limits from Swift/BAT-GUANO
  33. LIGO/Virgo/KAGRA S230928cb: Upper limits from Swift/BAT-GUANO
  34. GRB 230827B: 10.4m GTC spectroscopic redshift
  35. GRB 230930A: Fermi GBM Final Real-time Localization
  36. AT2023sva / GRB230916B: GIT observations of the afterglow
  37. transient AT2023sva: A Binary Driven Hypernova with a possible associated supernova
  38. Konus-Wind detection of GRB 230919A
  39. LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
  40. LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
  41. LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO
  42. Fermi Gamma-ray Burst Monitor trigger 717299390/230925076 is not a GRB
  43. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  44. GRB 230812B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  45. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  46. GRB 230921A: Fermi GBM Final Real-time Localization
  47. GRB 230918B: VLT/X-shooter classification of AT 2023tbf (GOTO23aky) as a dwarf nova
  48. IPN triangulation of GRB 230919A (short)
  49. LIGO/Virgo/KAGRA S230904n: Classification of the candidate AT2023rkw with DBSP
  50. GRB 230919A: Fermi GBM Observation
  51. Fermi GBM Statement for Trigger 716527670/230916144
  52. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  53. GRB 230812B : optical observations from MISTRAL at Observatoire de Haute-Provence
  54. GRB 230919A: AstroSat CZTI detection
  55. AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
  56. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  57. GRB 230919A: Fermi GBM Final Real-time Localization
  58. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT
  59. GRB 230918B: Fermi GBM Final Real-time Localization
  60. GRB 230918A (short): Glowbug gamma-ray detection
  61. GRB 230916B: Glowbug gamma-ray detection
  62. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  63. GRB 230915A: Fermi GBM observation
  64. GRB 230812B: Radio observations with the uGMRT
  65. GRB 230918A: Fermi GBM Final Real-time Localization
  66. GRB 230917A: AstroSat CZTI detection
  67. GRB 230915B: Glowbug gamma-ray detection
  68. GRB 230916A: NuSTAR Discovery of Prompt Emission from a Potential GRB
  69. GRB 230911A: Fermi GBM Observation
  70. Swift GRB230916.18: Global MASTER-Net observations report
  71. Fermi trigger No 716572242: Global MASTER-Net observations report
  72. Fermi trigger No 716544961: Global MASTER-Net observations report
  73. GRB 230915A: Swift/BAT-GUANO detection of a burst
  74. LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO
  75. GRB 230911D: GRBAlpha detection
  76. Swift GRB230916.19: Global MASTER-Net observations report
  77. Swift GRB230916.18: Global MASTER-Net observations report
  78. Swift GRB230916.13: Global MASTER-Net observations report
  79. Swift GRB230916.12: Global MASTER-Net observations report
  80. Swift GRB230916.11: Global MASTER-Net observations report
  81. Swift Trigger 1192233 is not a GRB
  82. GRB 230906A: optical counterpart
  83. GRB 230911A: Swift-XRT afterglow detection
  84. Fermi trigger No 716449174: Global MASTER-Net observations report
  85. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  86. IceCube Alert 230914.22: Global MASTER-Net observations report
  87. Fermi trigger No 716419312: Global MASTER-Net observations report
  88. GRB 230913A: Glowbug gamma-ray detection
  89. GRB 230812B: Bad Time Intervals for Fermi GBM data
  90. IceCube-230914A - IceCube observation of a high-energy neutrino candidate track-like event
  91. Swift GRB230913.70: Global MASTER-Net observations report
  92. GRB 230913A: Fermi GBM Observation
  93. LIGO/Virgo/KAGRA S230904n: One ZTF candidate counterpart to coincident neutrino event
  94. Swift Trigger 1191904 is not a GRB
  95. Swift GRB230913.70: Global MASTER-Net observations report
  96. GRB 230911A: Swift ToO observations
  97. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  98. Fermi GRB 230913A: Global MASTER-Net observations report
  99. GRB 230911A: GOTO optical counterpart candidate
  100. GRB 230913A: Fermi GBM Final Real-time Localization

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