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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"

32532 results found.

  1. GRB 230812B: GIT Confirmation of SN rise
  2. LIGO/Virgo/KAGRA S230819ax: Updated Sky localization
  3. GRB 230818A: Nickel and KAIT telescope optical observations
  4. GRB 230818A: SAO RAS 6-m telescope spectroscopy
  5. GRB 230812B: SAO RAS Zeiss-1000 observations
  6. GRB 230818A: further SAO RAS Zeiss-1000 observations
  7. LIGO/Virgo/KAGRA S230819ax: Identification of a GW compact binary merger candidate
  8. GRB 230818A: AKO Upper Limit
  9. GRB 230818A: AstroSat CZTI detection
  10. GRB 230818A: Tautenburg observations
  11. GRB 230818A: Leavitt Observatory upper limit
  12. GRB 230818A: Bassano Bresciano Observatory optical observations
  13. GRB 230818A: KGO RC-25 optical observations
  14. GRB 230818A: Swift/UVOT Detection
  15. GRB 230818A: NOT photometry and spectroscopy
  16. GRB 230818A: SAO RAS Zeiss-1000 observations
  17. Fermi GRB 230818A: Global MASTER-Net observations report
  18. GRB 230818A: GOTO optical afterglow detection
  19. GRB 230812B: SAO RAS observations, possible re-brightening
  20. GRB 230816A: Swift-BAT refined analysis
  21. GRB 230816A: SVOM/C-GFT optical detection
  22. GRB 230817A: AstroSat CZTI detection
  23. GRB 230812B: SAO RAS optical observations
  24. GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
  25. GRB 230812B: NOEMA detection
  26. GRB 230815A: VLT/HAWK-I near-infrared afterglow detection
  27. Fermi GRB 230817A: Global MASTER-Net observations report
  28. GRB 230812B: optical photometry from Konkoly
  29. GRB 230812B: SAO RAS optical observations
  30. GRB230816A: Possible host and GIT detection of optical counterpart
  31. GRB 230816A: Tautenburg observations
  32. GRB 230816A: AKO Optical Observations
  33. GRB 230816A: TShAO and Assy optical observations
  34. GRB 230816A: SAO RAS optical observations
  35. IPN triangulation of GRB 230815B
  36. GRB 230816A: Nanshan/HMT optical afterglow detection
  37. GRB 230815A: SOAR/Goodman follow-up imaging
  38. GRB 230815A: Swift-BAT refined analysis
  39. GRB230815A: Swift/UVOT upper limits
  40. GRB 230812B: GAD Observatory optical observations (upper limit)
  41. GRB 230812B: iTelescope optical upper limit
  42. GRB 230812B: continued SAO RAS optical observation
  43. GRB 230815A: Fermi GBM detection
  44. Swift GRB 230815A: Global MASTER-Net observations report
  45. Fermi GRB 230814A: Global MASTER-Net observations report
  46. GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
  47. GRB 230812B: Tautenburg observations
  48. GRB 230812B: AMI-LA radio detection of afterglow candidate
  49. GRB 230812B: continued AbAO optical afterglow observations
  50. GRB 230812B: Optical observaions from Rozhen Observatory
  51. GRB 230812B: Further Bassano Bresciano Observatory optical observations
  52. LIGO/Virgo/KAGRA S230814ah: Identification of a GW compact binary merger candidate
  53. GRB 230812B: further SAO RAS optical observations
  54. GRB 230812B: Upper limits from a neutrino search with IceCube
  55. LIGO/Virgo/KAGRA S230814r: Updated Sky localization
  56. GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow
  57. GRB 230812B: CrAO ZTSh optical observations
  58. GRB 230812B: Koshka Zeiss-1000 optical observations
  59. GRB 230812B: GIT optical follow-up
  60. GRB 230812B: Leavitt Observatory optical observations
  61. GRB 230812B : optical observations from Observatoire de Haute-Provence
  62. GRB 230812B: Bassano Bresciano Observatory optical observations
  63. GRB 230812B: Faulkes Telescope North optical afterglow follow-up
  64. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  65. GRB 230812B: rest-frame energetics from Konus-Wind observation
  66. GRB 230812B: OASDG optical observations
  67. GRB 230812B: AbAO optical observations
  68. LIGO/Virgo/KAGRA S230814r: Identification of a GW compact binary merger candidate
  69. GRB 230812B: Spectroscopy from NOT
  70. GRB 230812B: Redshift from OSIRIS+/GTC
  71. GRB 230812B: Montarrenti Observatory optical observations
  72. GRB 230812B: SAO RAS optical observations
  73. GRB 230812B: Detected Optical Afterglow Candidate
  74. GRB 230812B: GMG - GRANDMA observations
  75. Konus-Wind detection of GRB 230812B
  76. GRB 230812B: GECAM-C observation of a very bright burst
  77. GRB 230812: Swift/UVOT Detection
  78. GOTO confirmation and possible host galaxy of GRB230812B optical afterglow
  79. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  80. Fermi GRB 230812B: MASTER optical counterpart
  81. GRB 230812B: KAIT Optical Afterglow Candidate
  82. GRB 230812B: Improved Swift/XRT localization
  83. GRB 230812B: Preliminary Swift/XRT localization
  84. GRB 230812B: Fermi-LAT detection
  85. GRB 230812B: Fermi GBM Observation of a very bright burst
  86. Fermi GRB 230812B: Global MASTER-Net observations report
  87. GRB 230812B: Tiled Swift observations
  88. ZTF23aaoohpy/AT2023lcr: JWST spectroscopy confirmation of an associated type Ic-BL supernova
  89. LIGO/Virgo/KAGRA S230811n: Updated Sky localization
  90. GRB 230808A: Fermi GBM Detection
  91. LIGO/Virgo/KAGRA S230811n: Identification of a GW compact binary merger candidate
  92. GRB 230805B: Swift-BAT refined analysis
  93. GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
  94. GRB 230805B: AstroSat CZTI detection
  95. GRB 230808A: Swift/BAT-GUANO detection of a burst
  96. The Fermi GBM Trigger 713134237 / 230807868 is not associated with LIGO/Virgo/KAGRA S230807f.
  97. ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
  98. GRB 230805B : MITSuME Akeno optical upper limits
  99. LIGO/Virgo/KAGRA S230808i: Identification of a GW unmodeled transient candidate
  100. LIGO/Virgo/KAGRA S230807f: Updated Sky localization and EM Bright Classification

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