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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"

32795 results found.

  1. LIGO/Virgo/KAGRA S230924an: Identification of a GW compact binary merger candidate
  2. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  3. LIGO/Virgo/KAGRA S230922g: Updated Sky localization
  4. LIGO/Virgo/KAGRA S230922g: Identification of a GW compact binary merger candidate
  5. LIGO/Virgo/KAGRA S230922q: Identification of a GW compact binary merger candidate
  6. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  7. GRB 230918B: VLT/X-shooter classification of AT 2023tbf (GOTO23aky) as a dwarf nova
  8. IPN triangulation of GRB 230919A (short)
  9. LIGO/Virgo/KAGRA S230904n: Classification of the candidate AT2023rkw with DBSP
  10. GRB 230919A: Fermi GBM Observation
  11. Correction to Fermi GBM Statement for Trigger 716527670/230916144
  12. Fermi GBM Statement for Trigger 716527670/230916144
  13. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  14. LIGO/Virgo/KAGRA S230920al: Updated Sky localization
  15. LIGO/Virgo/KAGRA S230919bj: Updated Sky localization
  16. transient AT2023sva: imaging and spectroscopic observations from MISTRAL at Observatoire de Haute-Provence
  17. GRB 230812B : optical observations from MISTRAL at Observatoire de Haute-Provence
  18. GRB 230919A: AstroSat CZTI detection
  19. LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
  20. AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
  21. LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
  22. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  23. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  24. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT
  25. GRB 230918A (short): Glowbug gamma-ray detection
  26. AT 2023sva: NOT observations of the ZTF candidate afterglow
  27. GRB 230915A: Fermi GBM observation
  28. GRB 230812B: Radio observations with the uGMRT
  29. GRB 230917A: AstroSat CZTI detection
  30. Swift Triggers 1192480, 1192481, 1192482 and 1192483 are not astrophysical events
  31. GRB 230911A: Fermi GBM Observation
  32. LIGO/Virgo/KAGRA S230904n: Correction of the coordinates of the ZTF candidate counterpart
  33. Fermi-LAT gamma-ray observations of IceCube-230914A
  34. GRB 230911D: GRBAlpha detection
  35. Swift Triggers 1192234, 1192235 and 1192236 are not astrophysical events
  36. GRB 230906A: optical counterpart
  37. IceCube-230914A: Upper limits from a search for additional neutrino events in IceCube
  38. GRB 230911A: Swift-XRT afterglow detection
  39. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  40. GRB 230913A: Glowbug gamma-ray detection
  41. LIGO/Virgo/KAGRA S230914ak: Updated Sky localization
  42. LIGO/Virgo/KAGRA S230914ak: Identification of a GW compact binary merger candidate
  43. GRB 230913A: Fermi GBM Observation
  44. LIGO/Virgo/KAGRA S230904n: One ZTF candidate counterpart to coincident neutrino event
  45. GRB 230911A: Swift ToO observations
  46. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  47. Fermi GRB 230913A: Global MASTER-Net observations report
  48. GRB 230911A: GOTO optical counterpart candidate
  49. GRB 230908A: CALET Gamma-Ray Burst Monitor detection
  50. GRB 230911D: NuSTAR Detection of Prompt Emission
  51. GRB 230911B: AstroSat CZTI detection
  52. GRB 230911C: Swift-BAT refined analysis
  53. LIGO/Virgo/KAGRA S230911ae: Updated Sky localization
  54. GRB 230906A: Chandra detection of the X-ray afterglow
  55. Swift GRB 230911C: Global MASTER-Net observations report
  56. GRB 230911D: Fermi GBM observation
  57. IPN triangulation of GRB 230911D (long)
  58. GRB 230911D: Fermi-LAT detection
  59. GRB230911C: LCOGT Optical Upper Limits
  60. LIGO/Virgo/KAGRA S230911ae: Identification of a GW compact binary merger candidate
  61. GRB 230911C: Swift/UVOT Upper Limits
  62. GRB 230911B: GRBAlpha and VZLUSAT-2 joint detection
  63. GRB 230911C: GOTO optical upper limits
  64. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  65. GRB 230911B: correction to the KW GCN 34659
  66. Konus-Wind detection of GRB 230811D
  67. GRB 230911C: Swift detection of a burst
  68. Fermi GRB 230911B: Global MASTER-Net observations report
  69. GRB 230906A: BlackGEM upper limits
  70. GRB 230903A: TESS observations of optical emission
  71. GRB 230906A: AstroSat CZTI detection
  72. GRB 230908A: GRBAlpha detection
  73. Glowbug gamma-ray detection GRB 230905B
  74. GRB 230906A: Swift/UVOT Upper Limits
  75. GRID detection of GRB 230827A
  76. GRB 230818A: radio observation with the VLA
  77. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  78. GRB 230906A: Swift-XRT observations
  79. Konus-Wind detection of GRB 230906A (short)
  80. IPN triangulation of GRB 230906A (short)
  81. GRB 230906A: Swift ToO observations
  82. GRB 230905B: AstroSat CZTI detection
  83. Fermi GRB 230906A: Global MASTER-Net observations report
  84. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  85. LIGO/Virgo/KAGRA S230904n: Updated Sky localization and EM Bright Classification
  86. GRB 230903A: VLT/X-shooter optical observations
  87. GRB 230903A: Swift-BAT refined analysis
  88. Fermi GRB 230903A: Global MASTER-Net observations report
  89. GRB 230903A: Fermi GBM detection
  90. GRB 230904B is not a GRB
  91. Fermi GRB 230904A: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S230904n: Identification of a GW compact binary merger candidate
  93. GRB 230903A: LCOGT Optical Upper Limits
  94. LIGO/Virgo/KAGRA S230831e: Updated Sky localization
  95. LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
  96. GRB 230827B: Glowbug gamma-ray detection
  97. GRB 230827A: Glowbug gamma-ray detection
  98. GRB 230826A: Glowbug gamma-ray detection
  99. GRB 230827B: Swift-XRT afterglow detection
  100. LIGO/Virgo/KAGRA S230715bw: Reissue of Retraction of GW compact binary merger candidate

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