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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"

28104 results found.

  1. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  2. GRB 230826A: VZLUSAT-2 detection
  3. GRB 230827B: VZLUSAT-2 detection
  4. GRB 230827B / GRB 230827256: Fermi GBM Observation
  5. Subject: GRB230826A: Swift/UVOT upper limits
  6. GRB 230827A: BALROG localization (Fermi Trigger / GRB 230827762)
  7. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  8. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  9. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  10. GRB 230826A: Fermi GBM Observation
  11. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  12. GRB 230826A: Enhanced Swift-XRT position
  13. GRB 230826A: Swift-XRT refined Analysis
  14. GRB 230826A: Mondy optical observations
  15. Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
  16. GRB 230826A: Swift detection of a burst
  17. Swift J1727.8-1613 (GRB 230824A): Bassano Bresciano Observatory optical observations
  18. LIGO/Virgo/KAGRA S230825k: Upper limits from Swift/BAT-GUANO
  19. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  20. GRB 230812B: radio detection with the VLA
  21. LIGO/Virgo/KAGRA S230825k: Updated Sky localization
  22. LIGO/Virgo/KAGRA S230825k: Identification of a GW compact binary merger candidate
  23. GRB 230824A: AKO Optical Afterglow Candidate
  24. LIGO/Virgo/KAGRA S230824r: Updated Sky localization
  25. LIGO/Virgo/KAGRA S230824r: Identification of a GW compact binary merger candidate
  26. LIGO/Virgo/KAGRA S230822bm: Upper limits from Swift/BAT-GUANO
  27. GRB 230822A: Swift/BAT-GUANO detection of a burst
  28. GRB 230818B: VZLUSAT-2 detection
  29. LIGO/Virgo/KAGRA S230822bm: Updated Sky localization
  30. LIGO/Virgo/KAGRA S230822bm: Identification of a GW compact binary merger candidate
  31. GRB 230812B: Assy optical observations, possible SN rise
  32. GRB 230812B: SAO RAS RC-500 and Zeiss-1000 observations
  33. GRB 230818A: Swift-BAT refined analysis
  34. GRB 20230818A: GIT optical upper limit
  35. GRB 230812B : GRANDMA/Kilonova-Catcher optical afterglow detection and upper limits
  36. LIGO/Virgo/KAGRA S230820bq: Identification of a GW compact binary merger candidate
  37. Swift Triggers 1186280 and 1186291 are not GRBs
  38. GRB 230818A: Fermi GBM Observation
  39. GRB 230812B: GIT Confirmation of SN rise
  40. LIGO/Virgo/KAGRA S230819ax: Updated Sky localization
  41. GRB 230818A: Nickel and KAIT telescope optical observations
  42. GRB 230812B: SAO RAS Zeiss-1000 observations
  43. GRB 230818A: further SAO RAS Zeiss-1000 observations
  44. LIGO/Virgo/KAGRA S230819ax: Identification of a GW compact binary merger candidate
  45. GRB 230818A: AKO Upper Limit
  46. GRB 230818A: Tautenburg observations
  47. GRB 230818A: Leavitt Observatory upper limit
  48. GRB 230818A: Swift-XRT refined Analysis
  49. GRB 230818A: Bassano Bresciano Observatory optical observations
  50. GRB 230818A: KGO RC-25 optical observations
  51. GRB 230818A: Swift/UVOT Detection
  52. GRB 230818A: Enhanced Swift-XRT position
  53. GRB 230818A: SAO RAS Zeiss-1000 observations
  54. Fermi trigger No 713974668: Global MASTER-Net observations report
  55. GRB 230818A: GOTO optical afterglow detection
  56. GRB 230818A: Swift detection of a burst
  57. Swift GRB230818.98: Global MASTER-Net OT detection
  58. GRB 230812B: SAO RAS observations, possible re-brightening
  59. GRB 230816A: Swift-BAT refined analysis
  60. GRB 230812B: SAO RAS optical observations
  61. GRB 230816A: Swift-XRT refined Analysis
  62. GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
  63. GRB 230815A: VLT/HAWK-I near-infrared afterglow detection
  64. GRB 230817A: BALROG localization (Fermi Trigger 713966581 / GRB 230817502)
  65. GRB 230816A: Enhanced Swift-XRT position
  66. GRB 230812B: SAO RAS optical observations
  67. GRB230816A: Possible host and GIT detection of optical counterpart
  68. GRB 230816A: Tautenburg observations
  69. GRB 230816A: AKO Optical Observations
  70. GRB 230816A: TShAO and Assy optical observations
  71. GRB 230816A: SAO RAS optical observations
  72. IPN triangulation of GRB 230815B
  73. GRB 230816A: Nanshan/HMT optical afterglow detection
  74. GRB 230816A: Swift detection of a burst
  75. GRB 230815A: Swift-BAT refined analysis
  76. GRB 230815B: GECAM-B and GECAM-C detection of a burst
  77. GRB230815A: Swift/UVOT upper limits
  78. GRB 230812B: GAD Observatory optical observations (upper limit)
  79. GRB 230815A: Swift-XRT refined Analysis
  80. GRB 230812B: iTelescope optical upper limit
  81. GRB 230812B: continued SAO RAS optical observation
  82. GRB 230815A: Fermi GBM detection
  83. GRB 230815A: Enhanced Swift-XRT position
  84. GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
  85. GRB 230812B: Tautenburg observations
  86. GRB 230815A: Swift detection of a burst
  87. GRB 230812B: AMI-LA radio detection of afterglow candidate
  88. GRB 230812B: continued AbAO optical afterglow observations
  89. GRB 230812B: Optical observaions from Rozhen Observatory
  90. GRB 230812B: Further Bassano Bresciano Observatory optical observations
  91. LIGO/Virgo/KAGRA S230814ah: Identification of a GW compact binary merger candidate
  92. GRB 230812B: further SAO RAS optical observations
  93. GRB 230812B: Upper limits from a neutrino search with IceCube
  94. LIGO/Virgo/KAGRA S230814r: Updated Sky localization
  95. GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow
  96. GRB 230814A: BALROG localization (Fermi Trigger 713732101 / GRB 230814788)
  97. GRB 230812B: CrAO ZTSh optical observations
  98. GRB 230812B: Koshka Zeiss-1000 optical observations
  99. GRB 230812B: GIT optical follow-up
  100. GRB 230812B: Leavitt Observatory optical observations

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