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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"

28688 results found.

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

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