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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"

28709 results found.

  1. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  2. GRB 220325A: GRANDMA observations
  3. GRB 220320A: Detection by VZLUSAT-2
  4. Konus-Wind observation of GRB 220320A
  5. GRB 220325A: Swift/UVOT Upper Limits
  6. GRB 211024B: Host galaxy redshift from X-shooter/VLT
  7. GRB 220325A: Swift-BAT refined analysis
  8. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
  9. GRB 220325A: Tautenburg observations
  10. GRB 220325A: LCO Optical Upper Limits
  11. GRB 220325A: Swift-XRT refined Analysis
  12. GRB 220325A: 1.3m DFOT Optical upper limit
  13. Fermi GBM Sub-Threshold Detection of GRB 220325A
  14. GRB 220325A: MASTER Global Robotic Net optical observations
  15. GRB 220323A: AstroSat CZTI detection
  16. GRB 220319A: GRANDMA observations
  17. GRB 220323A: AGILE/MCAL detection
  18. IPN triangulation of GRB 220320A
  19. GRB 220319A: Swift-BAT refined analysis
  20. GRB 220316A: AstroSat CZTI detection
  21. GRB 220320A: AstroSat CZTI detection
  22. GRB 220317A: Fermi GBM detection
  23. GRB 220319A: MITSuME Akeno optical upper limits
  24. GRB220319A: Optical observations from NOT
  25. GRB 220319A: LCO Optical Upper Limit
  26. GRB 220319A: Mondy optical uper limit
  27. GRB 220319A: Swift-XRT refined Analysis
  28. GRB 220319A: MASTER Global Robotic Net optical observations
  29. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  30. GRB 220317A: Swift/BAT-GUANO detection outside the coded FOV
  31. GRB 220310A: MITSuME Akeno optical observation
  32. IceCube-220317A: MASTER Global Robotic Net optical observations
  33. GRB 220315A: MASTER Global Robotic Net optical observations
  34. GRB 220311A: Fermi GBM observation
  35. GRB 220306B: Swift/UVOT Upper Limits
  36. GRB 220311A: MITSuME Akeno optical upper limits
  37. IPN triangulation of GRB 220310A
  38. GRB 220310C: Fermi GBM observation
  39. GRB 210722A: TAROT Reunion observatory optical light curve
  40. GRB 210222B: TAROT Reunion observatory optical light curve
  41. GRB 201021C: TAROT Reunion observatory optical light curve
  42. GRB 220310A: K-800 of Terskol observatory optical upper limit
  43. GRB 220310A: [KAO-Egypt] SDSS r, i observation
  44. Konus-Wind detection of GRB 220310A
  45. GRB 220310C: Swift ToO observations
  46. GRB 220310C: Swift/BAT-GUANO candidate arcminute localization
  47. GRB 220311A: MASTER OT retraction
  48. ZTF22aabjpxh/AT2022cva (GRB 220219B): evidence of supernova in LBT spectra
  49. GRB 220310A: GIT confirmation of optical afterglow.
  50. GRB 220306B: Nanshan/NEXT optical upper limit
  51. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
  52. Fermi GBM Detection of GRB 220308A
  53. GRB 220308A: AGILE detection
  54. GRB 220310A: MASTER optical counterpart detection
  55. GRB 220310A: Swift ToO observations
  56. GRB 220310A: CALET Gamma-Ray Burst Monitor detection
  57. ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
  58. Fermi GRB 220310B: Global MASTER-Net observations report
  59. Konus-Wind detection of GRB 220308A
  60. IceCube-220306A: No significant detection in HAWC
  61. IceCube-220303A: No significant detection in HAWC
  62. ZTF22aabjpxh/AT2022cva: AMI-LA radio observation
  63. CALET Gamma-Ray Burst Monitor detection of GRB 220308A and its possible precursor
  64. Fermi GRB 220309A: Global MASTER-Net observations report
  65. GRB 220308A: Swift/BAT-GUANO detection outside the coded FOV
  66. IPN triangulation of GRB 220308A (long / very bright)
  67. GRB 220306B: Mondy optical observations, confirmation afterglow candidate
  68. IPN triangulation of GRB 220305B
  69. GRB 220306B: Tautenburg observations
  70. GRB 220304A Fermi GBM detection
  71. GRB 220306B: Swift-BAT refined analysis
  72. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  73. GRB 220306B: AbAO optical observations, possible afterglow candidate
  74. GRB 220306B: Swift-XRT refined Analysis
  75. GRB 220306B: Fermi GBM observation
  76. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  77. Swift GRB 220306B: Global MASTER-Net observations report
  78. GRB 220305A: Swift-BAT refined analysis
  79. Fermi GBM Sub-Threshold Detection of GRB 220305A
  80. GRB 220305A: Swift-XRT refined Analysis
  81. Fermi GRB 220306A: Global MASTER-Net observations report
  82. Fermi GRB 220305A: Global MASTER-Net observations report
  83. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  84. IceCube-220303A: One X-ray counterpart from Swift/XRT follow up observations
  85. Swift GRB 220305A: Global MASTER-Net observations report
  86. ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, SN signature search
  87. GRB 220302A: Swift/UVOT Upper Limits
  88. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  89. GRB 220304A: Swift/BAT-GUANO detection outside the coded FOV
  90. Fermi GRB 220304A: Global MASTER-Net observations report
  91. GRB 220302A: Swift-XRT refined Analysis
  92. ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
  93. ZTF22aaajecp/AT2022cmc: ATCA detection
  94. GRB 220302A: Swift afterglow detection
  95. GRB 220222A: CALET Gamma-Ray Burst Monitor detection
  96. Swift GRB 220302A: Global MASTER-Net observations report
  97. GRB 220228A: Fermi GBM observation
  98. GRB 220228A: Fermi-LAT detection
  99. Konus-Wind detection of GRB 220222A
  100. ZTF22aaajecp/AT2022cmc: JCMT SCUBA-2 sub-mm observations

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