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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"

16152 results found.

  1. GRB 211207A: VLT/X-shooter redshift
  2. GRB 211207A: Swift detection of a burst with an optical counterpart
  3. GRB 211129A: Swift/UVOT Upper Limits
  4. GRB 211106A: HST Observations
  5. GRB 211129A: Nanshan/NEXT optical upper limit
  6. GRB 211129A: MITSuME Akeno optical upper limits
  7. GRB 211023A: Xinglong 2.16m optical observations
  8. GRB 211023A: Xinglong 2.16m optical observations
  9. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  10. Fermi-LAT Gamma-ray Observations of IceCube-211123A
  11. GRB 211023A: optical observations and photometric evidence of supernova
  12. Fermi-LAT Gamma-ray Observations of IceCube-211117A
  13. Fermi-LAT Gamma-ray Observations of IceCube-211116A
  14. GRB 211106A: VLT/FORS2 optical observations
  15. GRB 211023A: SAO RAS optical observations
  16. MeerLICHT follow-up of GRB 211106A
  17. GRB 211023A: A BdHN of type I
  18. GRB 211023A: BTA spectroscopic redshift
  19. GRB 211105A: MASTER optical inspection
  20. GRB 211023A: optical detection by SBT in Ondrejov
  21. GRB 211023A: continued 1.3m DFOT Optical Observations and possible jet break
  22. GRB 211023B: Subaru optical observation
  23. GRB 211024A: MITSuME Akeno optical observation
  24. GRB 211023B: MITSuME Akeno optical upper limits
  25. GRB 211024B: Optical afterglow observation by Ondrejov D50
  26. GRB 211024A: 1.3m DFOT observations
  27. GRB 211023A: 1.3m DFOT Optical Observations
  28. GRB 2121023B: 6 GHz VLA radio upper limit
  29. GRB 211023A: Terskol optical observations
  30. GRB 211023A: continued Mondy optical observations
  31. GRB 211023B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  32. GRB 211025A: Optical Afterglow Detection
  33. GRB211023A: optical afterglow detection from Konkoly Observatory
  34. GRB 211023A: Mondy optical observations
  35. GRB 211023B: Mondy optical afterglow confirmation
  36. GRB 211023B: Gemini-North Optical Observations
  37. GRB 211023B: LDT Optical Afterglow Detection
  38. GRB 211024B: CAHA 2.2m Detection; ultra-long GRB?
  39. Possible Short GRB 211023B: CAHA 2.2m Detection
  40. GRB 211023A: 1.5m OSN optical observation
  41. GRB 210610B: Sintesz-Newton/CrAO optical observations
  42. GRB 211024B: Nanshan/NEXT optical afterglow detection
  43. Fermi-LAT Gamma-ray Observations of IceCube-211023A
  44. GRB 211023A: MASTER OT J045237.07+851925.2 - optical counterpart discovery
  45. GRB 211023B: BOOTES-4/MET and 1.5m OSN optical upper limit
  46. GRB 211023B: RATIR Optical and NIR Upper Limits
  47. GRB 211023B: TSHAO optical observation
  48. GRB 211023B: Swift detection of a possibly short burst with an optical counterpart
  49. BepiColombo MGNS joins the IPN
  50. Swift trigger 1078701: MITSuME Akeno optical upper limits
  51. GRB 210919A: LDT optical observations and candidate host galaxies
  52. IceCube-20210922A: No optical counterparts found by MITSuME observations
  53. Swift Trigger 1078701: Mondy, CrAO, AbAO observations, possible optical counterpart
  54. IceCube-20210922A: DESNU Optical counterpart candidate from 5 nights of DECam observations
  55. IceCube-210922A: DESI Observations
  56. GRB 210928A: Kinder SLT-40cm optical limits
  57. Swift GRB211001.03 / trigger 1076121 : MASTER OT retraction
  58. GRB 210930A: CAHA 2.2m telescope optical limit
  59. GRB 210927A: GIT optical follow-up of ZTF21acdwctm.
  60. Swift GRB211001.03: Global MASTER-Net OT detection
  61. GRB 210930A: Swift/UVOT Upper Limits
  62. Fermi-LAT Gamma-ray Observations of IceCubeCascade-210926A
  63. GRB 210919A: iTelescope T-11 upper limits
  64. IceCube-210922A: JCMT/SCUBA2 observations
  65. Fermi-LAT Gamma-ray Observations of IceCube-210922A
  66. GRB 210912A: LBT optical observations
  67. GRB 210919A: Swift/UVOT Upper Limits
  68. GRB 210919A: LOAO and LSGT optical upper limits
  69. GRB 210919A: MITSuME Akeno optical upper limits
  70. GRB 210919A: NOT upper limits
  71. GRB 210919A: AbAO optical upper limit
  72. GRB 210919A: LCO Optical Upper Limit
  73. GRB 210919A: BOOTES-2/TELMA optical upper limit
  74. GRB 210912A: BOOTES-5/JGT optical afterglow candidate (Correction to GCNC 30823)
  75. GRB 210912A: Tautenburg observations
  76. GRB 210912A: Swift/UVOT Detection
  77. GRB 210912A: Mondy optical afterglow confirmation
  78. GRB 210912A: BOOTES-5/JGT optical afterglow candidate
  79. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  80. GRB 210905A: Swift/UVOT Upper Limits
  81. GRB 210905A: ATCA detection
  82. GRB 210905A: ALMA detection
  83. GRB 210610A: Maidanak and AbAO optical observations
  84. GRB 210905A: REM NIR afterglow detection
  85. GRB 210905A: Continued LCO Optical Observations
  86. GRB 210905A: LCO Optical Detection
  87. GRB 210901A: Swift/UVOT Upper Limits
  88. GRB 210820A: TSHAO optical upper limit
  89. GRB 210901A: LCO Optical Upper Limit
  90. GRB 210827A: Swift/UVOT Upper Limits
  91. GRB 210827A: BOOTES-5/JGT optical upper limit
  92. GRB 210820A: CAHA 2.2m Optical Detection
  93. GRB 210824A: Swift/UVOT Upper Limits
  94. GRB 210826A: Swift/UVOT Upper Limits
  95. GRB 210822A: CAHA 2.2m observations
  96. GRB 210824A: MITSuME Akeno optical upper limits
  97. GRB 210822A: TSHAO continued optical observation
  98. GRB 210822A: VLA detection
  99. GRB 210822A: TSHAO optical observation
  100. GRB 210824A: BOOTES-5/JGT optical upper limit

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