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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"

32509 results found.

  1. GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
  2. GRB 230812B: NOEMA detection
  3. GRB 230815A: VLT/HAWK-I near-infrared afterglow detection
  4. Fermi GRB 230817A: Global MASTER-Net observations report
  5. GRB 230812B: optical photometry from Konkoly
  6. GRB 230812B: SAO RAS optical observations
  7. GRB230816A: Possible host and GIT detection of optical counterpart
  8. GRB 230816A: Tautenburg observations
  9. GRB 230816A: AKO Optical Observations
  10. GRB 230816A: TShAO and Assy optical observations
  11. GRB 230816A: SAO RAS optical observations
  12. IPN triangulation of GRB 230815B
  13. GRB 230816A: Nanshan/HMT optical afterglow detection
  14. GRB 230815A: SOAR/Goodman follow-up imaging
  15. GRB 230815A: Swift-BAT refined analysis
  16. GRB230815A: Swift/UVOT upper limits
  17. GRB 230812B: GAD Observatory optical observations (upper limit)
  18. GRB 230812B: iTelescope optical upper limit
  19. GRB 230812B: continued SAO RAS optical observation
  20. GRB 230815A: Fermi GBM detection
  21. Swift GRB 230815A: Global MASTER-Net observations report
  22. Fermi GRB 230814A: Global MASTER-Net observations report
  23. GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
  24. GRB 230812B: Tautenburg observations
  25. GRB 230812B: AMI-LA radio detection of afterglow candidate
  26. GRB 230812B: continued AbAO optical afterglow observations
  27. GRB 230812B: Optical observaions from Rozhen Observatory
  28. GRB 230812B: Further Bassano Bresciano Observatory optical observations
  29. LIGO/Virgo/KAGRA S230814ah: Identification of a GW compact binary merger candidate
  30. GRB 230812B: further SAO RAS optical observations
  31. GRB 230812B: Upper limits from a neutrino search with IceCube
  32. LIGO/Virgo/KAGRA S230814r: Updated Sky localization
  33. GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow
  34. GRB 230812B: CrAO ZTSh optical observations
  35. GRB 230812B: Koshka Zeiss-1000 optical observations
  36. GRB 230812B: GIT optical follow-up
  37. GRB 230812B: Leavitt Observatory optical observations
  38. GRB 230812B : optical observations from Observatoire de Haute-Provence
  39. GRB 230812B: Bassano Bresciano Observatory optical observations
  40. GRB 230812B: Faulkes Telescope North optical afterglow follow-up
  41. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  42. GRB 230812B: rest-frame energetics from Konus-Wind observation
  43. GRB 230812B: OASDG optical observations
  44. GRB 230812B: AbAO optical observations
  45. LIGO/Virgo/KAGRA S230814r: Identification of a GW compact binary merger candidate
  46. GRB 230812B: Spectroscopy from NOT
  47. GRB 230812B: Redshift from OSIRIS+/GTC
  48. GRB 230812B: Montarrenti Observatory optical observations
  49. GRB 230812B: SAO RAS optical observations
  50. GRB 230812B: Detected Optical Afterglow Candidate
  51. GRB 230812B: GMG - GRANDMA observations
  52. Konus-Wind detection of GRB 230812B
  53. GRB 230812B: GECAM-C observation of a very bright burst
  54. GRB 230812: Swift/UVOT Detection
  55. GOTO confirmation and possible host galaxy of GRB230812B optical afterglow
  56. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  57. Fermi GRB 230812B: MASTER optical counterpart
  58. GRB 230812B: KAIT Optical Afterglow Candidate
  59. GRB 230812B: Improved Swift/XRT localization
  60. GRB 230812B: Preliminary Swift/XRT localization
  61. GRB 230812B: Fermi-LAT detection
  62. GRB 230812B: Fermi GBM Observation of a very bright burst
  63. Fermi GRB 230812B: Global MASTER-Net observations report
  64. GRB 230812B: Tiled Swift observations
  65. ZTF23aaoohpy/AT2023lcr: JWST spectroscopy confirmation of an associated type Ic-BL supernova
  66. LIGO/Virgo/KAGRA S230811n: Updated Sky localization
  67. GRB 230808A: Fermi GBM Detection
  68. LIGO/Virgo/KAGRA S230811n: Identification of a GW compact binary merger candidate
  69. GRB 230805B: Swift-BAT refined analysis
  70. GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
  71. GRB 230805B: AstroSat CZTI detection
  72. GRB 230808A: Swift/BAT-GUANO detection of a burst
  73. The Fermi GBM Trigger 713134237 / 230807868 is not associated with LIGO/Virgo/KAGRA S230807f.
  74. ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
  75. GRB 230805B : MITSuME Akeno optical upper limits
  76. LIGO/Virgo/KAGRA S230808i: Identification of a GW unmodeled transient candidate
  77. LIGO/Virgo/KAGRA S230807f: Updated Sky localization and EM Bright Classification
  78. transient SPT-SVJ025406.5-702837: ATCA follow-up observations
  79. Fermi GRB 230807A: Global MASTER-Net observations report
  80. LIGO/Virgo/KAGRA S230807f: Identification of a GW compact binary merger candidate
  81. Konus-Wind detection of GRB 230803A
  82. GRB 230805B: Fermi GBM observation
  83. GRB 230805B : OHP/T193 optical upper limit
  84. LIGO/Virgo/KAGRA S230806ak: Updated Sky localization and EM Bright Classification
  85. LIGO/Virgo/KAGRA S230806ak: Identification of a GW compact binary merger candidate
  86. GRB 230805B: Swift/UVOT Upper Limits
  87. GRB 230805B: Bassano Bresciano observatory upper limit
  88. GRB 230805B: NOT optical afterglow confirmation
  89. Fermi GRB 230805A: Global MASTER-Net observations report
  90. Swift GRB 230805B: Global MASTER-Net observations report
  91. LIGO/Virgo/KAGRA S230805x: Updated Sky localization
  92. LIGO/Virgo/KAGRA S230805x: Identification of a GW compact binary merger candidate
  93. LIGO/Virgo/KAGRA S230802aq: Updated Sky localization and EM Bright Classification
  94. GRB 230802B: AstroSat CZTI detection
  95. GRB 230802A: Fermi GBM observation
  96. GRB 230802A: Swift-BAT refined analysis
  97. IPN triangulation of GRB 230803A
  98. GRB 230802A: Swift/UVOT Upper Limits
  99. GRB 230803A: AstroSat CZTI detection
  100. Swift GRB 230802A: Global MASTER-Net observations report

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