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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"

30632 results found.

  1. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  2. GRB 230911B: correction to the KW GCN 34659
  3. Konus-Wind detection of GRB 230811D
  4. GRB 230911C: Swift detection of a burst
  5. Fermi GRB 230911B: Global MASTER-Net observations report
  6. GRB 230906A: BlackGEM upper limits
  7. GRB 230903A: TESS observations of optical emission
  8. GRB 230906A: AstroSat CZTI detection
  9. GRB 230908A: GRBAlpha detection
  10. Glowbug gamma-ray detection GRB 230905B
  11. GRB 230906A: Swift/UVOT Upper Limits
  12. GRID detection of GRB 230827A
  13. GRB 230818A: radio observation with the VLA
  14. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  15. GRB 230906A: Swift-XRT observations
  16. Konus-Wind detection of GRB 230906A (short)
  17. IPN triangulation of GRB 230906A (short)
  18. GRB 230906A: Swift ToO observations
  19. GRB 230905B: AstroSat CZTI detection
  20. Fermi GRB 230906A: Global MASTER-Net observations report
  21. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  22. LIGO/Virgo/KAGRA S230904n: Updated Sky localization and EM Bright Classification
  23. GRB 230903A: VLT/X-shooter optical observations
  24. GRB 230903A: Swift-BAT refined analysis
  25. Fermi GRB 230903A: Global MASTER-Net observations report
  26. GRB 230903A: Fermi GBM detection
  27. GRB 230904B is not a GRB
  28. Fermi GRB 230904A: Global MASTER-Net observations report
  29. LIGO/Virgo/KAGRA S230904n: Identification of a GW compact binary merger candidate
  30. GRB 230903A: LCOGT Optical Upper Limits
  31. LIGO/Virgo/KAGRA S230831e: Updated Sky localization
  32. LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
  33. GRB 230827B: Glowbug gamma-ray detection
  34. GRB 230827A: Glowbug gamma-ray detection
  35. GRB 230826A: Glowbug gamma-ray detection
  36. GRB 230827B: Swift-XRT afterglow detection
  37. LIGO/Virgo/KAGRA S230715bw: Reissue of Retraction of GW compact binary merger candidate
  38. LIGO/Virgo/KAGRA S230820bq: Updated Sky localization
  39. GRB 230812B: Spectroscopic detection of the associated SN 2023pel.
  40. GRB 230827B: Swift ToO observations
  41. LIGO/Virgo/KAGRA S230814ah: Updated Sky localization
  42. GRB 230827A: Fermi GBM Observation
  43. GRB 230827B: CALET Gamma-Ray Burst Monitor detection
  44. GRB 230826A: Swift-BAT refined analysis
  45. GRB 230828A: AstroSat CZTI detection
  46. GRB 230827A: VZLUSAT-2 detection
  47. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  48. GRB 230826A: VZLUSAT-2 detection
  49. GRB 230827B: VZLUSAT-2 detection
  50. GRB 230827B / GRB 230827256: Fermi GBM Observation
  51. GRB 230827A: GRBAlpha detection
  52. Subject: GRB230826A: Swift/UVOT upper limits
  53. GRB 230827.256: AKO Optical follow-up of ZTF23abaanxz (AT 2023qxj)
  54. Fermi GRB 230827A: Global MASTER-Net observations report
  55. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  56. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  57. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  58. GRB 230826A: GRBAlpha detection
  59. GRB 230826A: Fermi GBM Observation
  60. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  61. GRB 230826A: Mondy optical observations
  62. Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
  63. GRB 230826A: Swift detection of a burst
  64. Swift J1727.8-1613 (GRB 230824A): Bassano Bresciano Observatory optical observations
  65. GRB 230824A: AKO Photometric Follow-up Observations
  66. GRB 230818B: CALET Gamma-Ray Burst Monitor detection
  67. Trigger 1187225: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  68. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  69. Trigger 1187207: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  70. Trigger 1187203: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  71. GRB 230812B: radio detection with the VLA
  72. NICER detection of Swift J1727.8-1613 (GRB 230824A)
  73. LIGO/Virgo/KAGRA S230825k: Updated Sky localization
  74. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  75. LIGO/Virgo/KAGRA S230825k: Identification of a GW compact binary merger candidate
  76. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  77. GRB 230824A: AKO Optical Afterglow Candidate
  78. Trigger 1186982: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  79. IBAS trigger 10375 is not a GRB
  80. GRB 230824A is likely a Galactic Transient: Swift J1727.8-1613
  81. LIGO/Virgo/KAGRA S230824r: Updated Sky localization
  82. LIGO/Virgo/KAGRA S230824r: Identification of a GW compact binary merger candidate
  83. GRB 230822A: Fermi GBM Observation
  84. GRB 230822A: Swift/BAT-GUANO detection of a burst
  85. IceCube-230823A: Event likely due to background
  86. GRB 230818B: VZLUSAT-2 detection
  87. GRB 230818B: AstroSat CZTI detection
  88. GRID detection of GRB 230818A
  89. LIGO/Virgo/KAGRA S230822bm: Updated Sky localization
  90. LIGO/Virgo/KAGRA S230822bm: Identification of a GW compact binary merger candidate
  91. GRB 230812B: Assy optical observations, possible SN rise
  92. GRB 230815A: ATCA detection of radio counterpart
  93. GRB 230812B: SAO RAS RC-500 and Zeiss-1000 observations
  94. GRB 230818A: Swift-BAT refined analysis
  95. GRB 20230818A: GIT optical upper limit
  96. Konus-Wind detection of GRB 230818A
  97. Swift triggers 1186294-1186304 are not astrophysical transients
  98. GRB 230812B : GRANDMA/Kilonova-Catcher optical afterglow detection and upper limits
  99. LIGO/Virgo/KAGRA S230820bq: Identification of a GW compact binary merger candidate
  100. GRB 230818A: Fermi GBM Observation

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