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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"

28718 results found.

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

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