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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"

28717 results found.

  1. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  2. GRB 220403A: Tautenburg observations
  3. Fermi GRB 220403A: Global MASTER-Net observations report
  4. GRB 220401A: Swift/BAT-GUANO detection outside the coded FOV
  5. GRB 220401A: Fermi GBM observation
  6. Fermi GRB 220401B: Global MASTER-Net observations report
  7. Fermi Gamma-ray Burst Monitor trigger 220331776/670444627 is not a GRB
  8. Fermi GRB 220330A: Global MASTER-Net observations report
  9. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  10. GRB 220325A: GRANDMA observations
  11. GRB 220320A: Detection by VZLUSAT-2
  12. Konus-Wind observation of GRB 220320A
  13. GRB 220325A: Swift/UVOT Upper Limits
  14. GRB 211024B: Host galaxy redshift from X-shooter/VLT
  15. GRB 220325A: Swift-BAT refined analysis
  16. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
  17. GRB 220325A: Tautenburg observations
  18. GRB 220325A: LCO Optical Upper Limits
  19. GRB 220325A: Swift-XRT refined Analysis
  20. GRB 220325A: 1.3m DFOT Optical upper limit
  21. Fermi GBM Sub-Threshold Detection of GRB 220325A
  22. GRB 220325A: MASTER Global Robotic Net optical observations
  23. GRB 220323A: AstroSat CZTI detection
  24. GRB 220319A: GRANDMA observations
  25. GRB 220323A: AGILE/MCAL detection
  26. IPN triangulation of GRB 220320A
  27. GRB 220319A: Swift-BAT refined analysis
  28. GRB 220316A: AstroSat CZTI detection
  29. GRB 220320A: AstroSat CZTI detection
  30. GRB 220317A: Fermi GBM detection
  31. GRB 220319A: MITSuME Akeno optical upper limits
  32. GRB220319A: Optical observations from NOT
  33. GRB 220319A: LCO Optical Upper Limit
  34. GRB 220319A: Mondy optical uper limit
  35. GRB 220319A: Swift-XRT refined Analysis
  36. GRB 220319A: MASTER Global Robotic Net optical observations
  37. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  38. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
  39. GRB 220310A: MITSuME Akeno optical observation
  40. IceCube-220317A: MASTER Global Robotic Net optical observations
  41. GRB 220315A: MASTER Global Robotic Net optical observations
  42. GRB 220311A: Fermi GBM observation
  43. GRB 220306B: Swift/UVOT Upper Limits
  44. GRB 220311A: MITSuME Akeno optical upper limits
  45. IPN triangulation of GRB 220310A
  46. GRB 220310C: Fermi GBM observation
  47. GRB 210722A: TAROT Reunion observatory optical light curve
  48. GRB 210222B: TAROT Reunion observatory optical light curve
  49. GRB 201021C: TAROT Reunion observatory optical light curve
  50. GRB 220310A: K-800 of Terskol observatory optical upper limit
  51. GRB 220310A: [KAO-Egypt] SDSS r, i observation
  52. Konus-Wind detection of GRB 220310A
  53. GRB 220310C: Swift ToO observations
  54. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  55. GRB 220311A: MASTER OT retraction
  56. ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
  57. GRB 220310A: GIT confirmation of optical afterglow.
  58. GRB 220306B: Nanshan/NEXT optical upper limit
  59. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  60. Fermi GBM Detection of GRB 220308A
  61. GRB 220308A: AGILE detection
  62. GRB 220310A: MASTER optical counterpart detection
  63. GRB 220310A: Swift ToO observations
  64. GRB 220310A: CALET Gamma-Ray Burst Monitor detection
  65. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  66. Fermi GRB 220310B: Global MASTER-Net observations report
  67. Konus-Wind detection of GRB 220308A
  68. IceCube-220306A: No significant detection in HAWC
  69. IceCube-220303A: No significant detection in HAWC
  70. ZTF22aabjpxh/AT2022cva: AMI-LA radio observation
  71. CALET Gamma-Ray Burst Monitor detection of GRB 220308A and its possible precursor
  72. Fermi GRB 220309A: Global MASTER-Net observations report
  73. GRB 220308A: Swift/BAT-GUANO detection outside the coded FOV
  74. IPN triangulation of GRB 220308A (long / very bright)
  75. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  76. IPN triangulation of GRB 220305B
  77. GRB 220306B: Tautenburg observations
  78. GRB 220304A Fermi GBM detection
  79. GRB 220306B: Swift-BAT refined analysis
  80. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  81. GRB 220306B: AbAO optical observations, possible afterglow candidate
  82. GRB 220306B: Swift-XRT refined Analysis
  83. GRB 220306B: Fermi GBM observation
  84. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  85. Swift GRB 220306B: Global MASTER-Net observations report
  86. GRB 220305A: Swift-BAT refined analysis
  87. Fermi GBM Sub-Threshold Detection of GRB 220305A
  88. GRB 220305A: Swift-XRT refined Analysis
  89. Fermi GRB 220306A: Global MASTER-Net observations report
  90. Fermi GRB 220305A: Global MASTER-Net observations report
  91. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  92. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  93. Swift GRB 220305A: Global MASTER-Net observations report
  94. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  95. GRB 220302A: Swift/UVOT Upper Limits
  96. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  97. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  98. Fermi GRB 220304A: Global MASTER-Net observations report
  99. GRB 220302A: Swift-XRT refined Analysis
  100. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection

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