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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"

28686 results found.

  1. GRB220319A: Optical observations from NOT
  2. GRB 220319A: LCO Optical Upper Limit
  3. GRB 220319A: Mondy optical uper limit
  4. GRB 220319A: Swift-XRT refined Analysis
  5. GRB 220319A: MASTER Global Robotic Net optical observations
  6. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  7. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
  8. GRB 220310A: MITSuME Akeno optical observation
  9. IceCube-220317A: MASTER Global Robotic Net optical observations
  10. GRB 220315A: MASTER Global Robotic Net optical observations
  11. GRB 220311A: Fermi GBM observation
  12. GRB 220306B: Swift/UVOT Upper Limits
  13. GRB 220311A: MITSuME Akeno optical upper limits
  14. IPN triangulation of GRB 220310A
  15. GRB 220310C: Fermi GBM observation
  16. GRB 210722A: TAROT Reunion observatory optical light curve
  17. GRB 210222B: TAROT Reunion observatory optical light curve
  18. GRB 201021C: TAROT Reunion observatory optical light curve
  19. GRB 220310A: K-800 of Terskol observatory optical upper limit
  20. GRB 220310A: [KAO-Egypt] SDSS r, i observation
  21. Konus-Wind detection of GRB 220310A
  22. GRB 220310C: Swift ToO observations
  23. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  24. GRB 220311A: MASTER OT retraction
  25. ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
  26. GRB 220310A: GIT confirmation of optical afterglow.
  27. GRB 220306B: Nanshan/NEXT optical upper limit
  28. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  29. Fermi GBM Detection of GRB 220308A
  30. GRB 220308A: AGILE detection
  31. GRB 220310A: MASTER optical counterpart detection
  32. GRB 220310A: Swift ToO observations
  33. GRB 220310A: CALET Gamma-Ray Burst Monitor detection
  34. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  35. Fermi GRB 220310B: Global MASTER-Net observations report
  36. Konus-Wind detection of GRB 220308A
  37. IceCube-220306A: No significant detection in HAWC
  38. IceCube-220303A: No significant detection in HAWC
  39. ZTF22aabjpxh/AT2022cva: AMI-LA radio observation
  40. CALET Gamma-Ray Burst Monitor detection of GRB 220308A and its possible precursor
  41. Fermi GRB 220309A: Global MASTER-Net observations report
  42. GRB 220308A: Swift/BAT-GUANO detection outside the coded FOV
  43. IPN triangulation of GRB 220308A (long / very bright)
  44. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  45. IPN triangulation of GRB 220305B
  46. GRB 220306B: Tautenburg observations
  47. GRB 220304A Fermi GBM detection
  48. GRB 220306B: Swift-BAT refined analysis
  49. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  50. GRB 220306B: AbAO optical observations, possible afterglow candidate
  51. GRB 220306B: Swift-XRT refined Analysis
  52. GRB 220306B: Fermi GBM observation
  53. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  54. Swift GRB 220306B: Global MASTER-Net observations report
  55. GRB 220305A: Swift-BAT refined analysis
  56. Fermi GBM Sub-Threshold Detection of GRB 220305A
  57. GRB 220305A: Swift-XRT refined Analysis
  58. Fermi GRB 220306A: Global MASTER-Net observations report
  59. Fermi GRB 220305A: Global MASTER-Net observations report
  60. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  61. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  62. Swift GRB 220305A: Global MASTER-Net observations report
  63. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  64. GRB 220302A: Swift/UVOT Upper Limits
  65. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  66. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  67. Fermi GRB 220304A: Global MASTER-Net observations report
  68. GRB 220302A: Swift-XRT refined Analysis
  69. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  70. ZTF22aaajecp/AT2022cmc: ATCA detection
  71. GRB 220302A: Swift afterglow detection
  72. GRB 220222A: CALET Gamma-Ray Burst Monitor detection
  73. Swift GRB 220302A: Global MASTER-Net observations report
  74. GRB 220228A: Fermi GBM observation
  75. GRB 220228A: Fermi-LAT detection
  76. Konus-Wind detection of GRB 220222A
  77. ZTF22aaajecp/AT2022cmc: JCMT SCUBA-2 sub-mm observations
  78. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  79. ZTF22aaajecp/AT2022cmc: Mondy optical observations
  80. IPN triangulation of GRB 220222A
  81. GRB 220101A: The first example of a Petanova
  82. Konus-Wind observation of GRB 220219B
  83. GCN Circ.draft on GRB 220222A
  84. GRB 220219B: Swift-XRT observations
  85. ZTF22aabjpxh/AT2022cva (GRB 220219B): Mondy optical observations
  86. Fermi GRB 220223A: Global MASTER-Net observations report
  87. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  88. ZTF22aabjpxh/AT2022cva: 1.5m OSN optical observation
  89. Fermi GRB 220222B: Global MASTER-Net observations report
  90. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  91. GRB 220219B: Swift ToO observations
  92. GRB 220222A: Swift/BAT-GUANO detection outside the coded FOV
  93. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  94. Fermi GRB 220222A: Global MASTER-Net observations report
  95. ZTF22aabjpxh/AT2022cva: Assy optical observations
  96. ZTF22aaajecb/AT2022cmc: Submillimeter Array detection
  97. ZTF22aaajecb/AT 2022cmc: CAHA 2.2m/CAFOS detection, luminous transient
  98. ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
  99. IPN triangulation of GRB 220219B (consistent with ZTF22aabjpxh/AT2022cva)
  100. Konus-Wind observation of GRB 220219A

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