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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

22216 results found.

  1. Konus-Wind detection of GRB 210702A
  2. GRB 210702A: Chilescope optical observations
  3. GRB 210702A: iTelescope optical afterglow observations
  4. GRB 210619B: JCMT SCUBA-2 sub-mm observations
  5. GRB 210610B: JCMT SCUBA-2 sub-mm observations
  6. GRB 210610A: JCMT SCUBA-2 sub-mm observations
  7. GRB 210702A: preliminary Swift/UVOT photometry
  8. GRB210702A: MeerLICHT multi-colour photometry
  9. Swift GRB 210702A: Global MASTER-Net observations report
  10. IceCube-210629A: One Candidate Counterpart from the Zwicky Transient Facility
  11. IceCube-210629A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  12. Fermi-LAT Gamma-ray Observations of IceCube-210629A
  13. IceCube-210629A: Upper limits from Fermi-GBM Observations
  14. IceCube Alert 210629.76: Global MASTER-Net observations report
  15. GRB 210619B: Sayan observatory 1.6-m telescope observations
  16. GRB 210626A: Swift/XRT afterglow confirmation
  17. Fermi trigger No 646443989: Global MASTER-Net observations report
  18. Fermi GRB 210627B: Global MASTER-Net observations report
  19. Fermi GRB 210627A: Global MASTER-Net observations report
  20. GRB 210626A: Swift-XRT afterglow detection
  21. Fermi trigger No 646322348: Global MASTER-Net observations report
  22. Fermi GRB 210626A: Global MASTER-Net observations report
  23. GRB 210626A: Swift ToO observations
  24. GRB 210626A: Swift/BAT-GUANO detection and arcminute localization
  25. GRB 150428A: late-time radio observations
  26. Fermi GRB 210625A: Global MASTER-Net observations report
  27. GRB210619B: optical afterglow detection from Konkoly Observatory
  28. GRB 210622A: Swift-XRT observations
  29. GRB 210610B: T-CAT optical observations
  30. Fermi trigger No 646189108: Global MASTER-Net observations report
  31. GRB 210618A: Swift-XRT afterglow detection
  32. Fermi trigger No 646194855: Global MASTER-Net observations report
  33. GRB 210622A: Swift ToO observations
  34. GRB 210619B: Even further SAO RAS optical observations
  35. GRB 210619B: Mini-MegaTORTORA early optical observations
  36. Fermi GRB 210622B: Global MASTER-Net observations report
  37. GRB 210619B: SPI-ACS/INTEGRAL observations
  38. GRB 210619B: Further SAO RAS optical observations
  39. GRB 210622A: Swift/BAT-GUANO detection and arcminute localization of a long burst
  40. GRB 210619B: AbAO optical observations
  41. Swift GRB210621.71: Global MASTER-Net observations report
  42. GRB 210619B: NOT optical observations
  43. GRB 210619B: 1.5m OSN optical observation
  44. GRB 210619B: SAO RAS optical observations
  45. GRB 210619B: SEDM Optical Observations
  46. GRB 210619B: TNG NIR observations of the afterglow
  47. GRB 210619B: REM optical/NIR afterglow detection
  48. Fermi GRB 210621A: Global MASTER-Net observations report
  49. GRB 210619B: GIT optical follow-up and confirmation of jet-break
  50. GRB 210619B: Liverpool Telescope First Hour Observations
  51. GRB 210619B: Swift/UVOT Detection
  52. GRB 210619B: Xinglong TNT optical observations
  53. Konus-Wind detection of GRB 210619B
  54. GRB 210619B: CAHA 2.2m photometric monitoring
  55. GRB 210619B: Liverpool Telescope r'-band observations
  56. GRB 210619B: Redshift from OSIRIS/GTC
  57. Fermi trigger No 645857659: Global MASTER-Net observations report
  58. GRB 210619B: Ondrejov D50 detection
  59. Swift GRB210619.99: Global MASTER-Net observations report
  60. GRB 210618A: Swift/UVOT Upper Limits
  61. GRB 210618A: Swift-XRT observations
  62. Swift GRB210618.07: Global MASTER-Net observations report
  63. GRB 210610B: Swift/UVOT Detection
  64. GRB 210610A: Swift/UVOT Detection
  65. GRB 210610B: CrAO/ZTSH continued optical observations and light curve
  66. Fermi trigger No 645485036: Global MASTER-Net observations report
  67. GRB 210610B: AbAO optical observations
  68. Fermi GRB 210615A: Global MASTER-Net observations report
  69. GRB 210610B: REM optical/NIR observations of the afterglow
  70. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  71. Swift ToO Observations of HAWC transient J0020+3108
  72. GRB 210605B: Swift-XRT afterglow detection
  73. GRB 210610A: Fermi GBM observations
  74. GRB 210610A: CAHA 2.2m Second Epoch
  75. GRB 210610B: iTelescope optical afterglow observations
  76. GRB 210610B: Further SAO RAS optical observations
  77. GRB 210610A: SAO RAS optical observations
  78. GRB 210610B: optical observations from Burke-Gaffney Observatory and Abbey Ridge Observatory
  79. Swift GRB210612.54: Global MASTER-Net observations report
  80. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  81. GRB 210610B: VLA detection
  82. GRB 210610B: ALMA detection
  83. GRB 210610B: CrAO/ZTSH optical observations and light curve
  84. GRB 210610A: CrAO/ZTSH optical observations
  85. GRB 210610B: CrAO/ZTSH optical observations (correction to the GCN circ. 30212)
  86. GRB 210610A: CrAO/ZTSH optical observations
  87. GRB 210610A: CAHA 2.2m observations and light-curve behavior
  88. GRB 210610B: Zwicky Transient Facility afterglow detection
  89. GRB 210610B: optical afterglow observations
  90. GRB 210610B: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  91. GRB 210610A: Spectroscopy and redshift confirmation with the Himalayan Chandra Telescope
  92. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  93. Konus-Wind detection of GRB 210610B
  94. GRB 210610B: GOTO confirmation of afterglow detection
  95. GRB 210610A: RATIR Optical and NIR Detection
  96. GRB 210610B: RATIR Optical and NIR Observations
  97. GRB 210610B: SAO RAS optical observations
  98. GRB 210610A: 1.5m OSN optical observation
  99. HAWC Transient Monitoring Alert: Significant Spot after 3 transits
  100. GRB 210610B: NOT optical observations and tentative redshift

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