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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"

32800 results found.

  1. GRB 230816A: TShAO and Assy optical observations
  2. GRB 230816A: SAO RAS optical observations
  3. IPN triangulation of GRB 230815B
  4. GRB 230816A: Nanshan/HMT optical afterglow detection
  5. GRB 230815A: SOAR/Goodman follow-up imaging
  6. GRB 230815A: Swift-BAT refined analysis
  7. GRB230815A: Swift/UVOT upper limits
  8. GRB 230812B: GAD Observatory optical observations (upper limit)
  9. GRB 230812B: iTelescope optical upper limit
  10. GRB 230812B: continued SAO RAS optical observation
  11. GRB 230815A: Fermi GBM detection
  12. Swift GRB 230815A: Global MASTER-Net observations report
  13. Fermi GRB 230814A: Global MASTER-Net observations report
  14. GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
  15. GRB 230812B: Tautenburg observations
  16. GRB 230812B: AMI-LA radio detection of afterglow candidate
  17. GRB 230812B: continued AbAO optical afterglow observations
  18. GRB 230812B: Optical observaions from Rozhen Observatory
  19. GRB 230812B: Further Bassano Bresciano Observatory optical observations
  20. LIGO/Virgo/KAGRA S230814ah: Identification of a GW compact binary merger candidate
  21. GRB 230812B: further SAO RAS optical observations
  22. GRB 230812B: Upper limits from a neutrino search with IceCube
  23. LIGO/Virgo/KAGRA S230814r: Updated Sky localization
  24. GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow
  25. GRB 230812B: CrAO ZTSh optical observations
  26. GRB 230812B: Koshka Zeiss-1000 optical observations
  27. GRB 230812B: GIT optical follow-up
  28. GRB 230812B: Leavitt Observatory optical observations
  29. GRB 230812B : optical observations from Observatoire de Haute-Provence
  30. GRB 230812B: Bassano Bresciano Observatory optical observations
  31. GRB 230812B: Faulkes Telescope North optical afterglow follow-up
  32. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  33. GRB 230812B: rest-frame energetics from Konus-Wind observation
  34. GRB 230812B: OASDG optical observations
  35. GRB 230812B: AbAO optical observations
  36. LIGO/Virgo/KAGRA S230814r: Identification of a GW compact binary merger candidate
  37. GRB 230812B: Spectroscopy from NOT
  38. GRB 230812B: Redshift from OSIRIS+/GTC
  39. GRB 230812B: Montarrenti Observatory optical observations
  40. GRB 230812B: SAO RAS optical observations
  41. GRB 230812B: Detected Optical Afterglow Candidate
  42. GRB 230812B: GMG - GRANDMA observations
  43. Konus-Wind detection of GRB 230812B
  44. GRB 230812B: GECAM-C observation of a very bright burst
  45. GRB 230812: Swift/UVOT Detection
  46. GOTO confirmation and possible host galaxy of GRB230812B optical afterglow
  47. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  48. Fermi GRB 230812B: MASTER optical counterpart
  49. GRB 230812B: KAIT Optical Afterglow Candidate
  50. GRB 230812B: Improved Swift/XRT localization
  51. GRB 230812B: Preliminary Swift/XRT localization
  52. GRB 230812B: Fermi-LAT detection
  53. GRB 230812B: Fermi GBM Observation of a very bright burst
  54. Fermi GRB 230812B: Global MASTER-Net observations report
  55. GRB 230812B: Tiled Swift observations
  56. ZTF23aaoohpy/AT2023lcr: JWST spectroscopy confirmation of an associated type Ic-BL supernova
  57. LIGO/Virgo/KAGRA S230811n: Updated Sky localization
  58. GRB 230808A: Fermi GBM Detection
  59. LIGO/Virgo/KAGRA S230811n: Identification of a GW compact binary merger candidate
  60. GRB 230805B: Swift-BAT refined analysis
  61. GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
  62. GRB 230805B: AstroSat CZTI detection
  63. GRB 230808A: Swift/BAT-GUANO detection of a burst
  64. The Fermi GBM Trigger 713134237 / 230807868 is not associated with LIGO/Virgo/KAGRA S230807f.
  65. ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
  66. GRB 230805B : MITSuME Akeno optical upper limits
  67. LIGO/Virgo/KAGRA S230808i: Identification of a GW unmodeled transient candidate
  68. LIGO/Virgo/KAGRA S230807f: Updated Sky localization and EM Bright Classification
  69. transient SPT-SVJ025406.5-702837: ATCA follow-up observations
  70. Fermi GRB 230807A: Global MASTER-Net observations report
  71. LIGO/Virgo/KAGRA S230807f: Identification of a GW compact binary merger candidate
  72. Konus-Wind detection of GRB 230803A
  73. GRB 230805B: Fermi GBM observation
  74. GRB 230805B : OHP/T193 optical upper limit
  75. LIGO/Virgo/KAGRA S230806ak: Updated Sky localization and EM Bright Classification
  76. LIGO/Virgo/KAGRA S230806ak: Identification of a GW compact binary merger candidate
  77. GRB 230805B: Swift/UVOT Upper Limits
  78. GRB 230805B: Bassano Bresciano observatory upper limit
  79. GRB 230805B: NOT optical afterglow confirmation
  80. Fermi GRB 230805A: Global MASTER-Net observations report
  81. Swift GRB 230805B: Global MASTER-Net observations report
  82. LIGO/Virgo/KAGRA S230805x: Updated Sky localization
  83. LIGO/Virgo/KAGRA S230805x: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S230802aq: Updated Sky localization and EM Bright Classification
  85. GRB 230802B: AstroSat CZTI detection
  86. GRB 230802A: Fermi GBM observation
  87. GRB 230802A: Swift-BAT refined analysis
  88. IPN triangulation of GRB 230803A
  89. GRB 230802A: Swift/UVOT Upper Limits
  90. GRB 230803A: AstroSat CZTI detection
  91. Swift GRB 230802A: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations
  93. LIGO/Virgo S230802aq: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  94. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  95. LIGO/Virgo/KAGRA S230802aq: Identification of a GW compact binary merger candidate
  96. IceCube-230724A: JCMT/SCUBA-2 submm observations
  97. IceCube-230707A: JCMT/SCUBA-2 submm observations
  98. GRB 230723A: SPT-3G millimeter-band transient event inconsistent with IPN position
  99. LIGO/Virgo/KAGRA S230731an: Updated Sky Localization and EM Bright Classification, and Correction to Source Classification
  100. LIGO/Virgo/KAGRA S230731an: Coverage and upper limits from MAXI/GSC observations

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