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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"

19701 results found.

  1. GRB 220101A: Tautenburg observations
  2. GRB 220101A: GMG observation (2nd epoch)
  3. GRB 211231A: AstroSat CZTI detection
  4. GRB 220101A: OASDG optical observations
  5. GRB 220101A: GMG observation
  6. GRB220101A: optical afterglow detection from Konkoly Observatory
  7. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  8. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  9. GRB 220101: Swift/UVOT Detection
  10. GRB 220101A: Enhanced Swift-XRT position
  11. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  12. IPN triangulation of GRB 211219A
  13. GRB 211229A: Swift ToO observations
  14. GRB 211227A: Swift/UVOT Upper Limits
  15. GRB 211227A: Liverpool Telescope upper limits
  16. GRB 211227A: Enhanced Swift-XRT position
  17. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  18. GRB 211221A: Swift/UVOT Upper Limits
  19. GRB 211227A: Swift detection of a burst
  20. GRB 211225B: Swift-BAT refined analysis
  21. GRB 211225A: MITSuME Akeno optical upper limits
  22. GRB 211225B: Swift detection of a burst
  23. Fermi GBM Sub-Threshold Detection of GRB 211207A
  24. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  25. GRB 211219B: AstroSat CZTI detection
  26. GRB 211219A: AstroSat CZTI detection
  27. GRB 211221A: Swift-XRT refined Analysis
  28. GRB 211218A: MITSuME Akeno optical upper limits
  29. GRB 211221A: MeerLICHT optical limits
  30. GRB 211221A: NOT optical limits
  31. GRB 211221A: Enhanced Swift-XRT position
  32. GRB 211221A: Swift detection of a burst
  33. IceCube-211216B: No significant detection in HAWC
  34. IceCube-211216A: No significant detection in HAWC
  35. GRB 211106A: XMM-Newton monitoring campaign detections
  36. Fermi-LAT Gamma-ray Observations of IceCube-211216B
  37. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  38. GRB 211211A: TNG NIR observations
  39. GRB 211211A - Gemini K-band detection
  40. GRB 211211A: SAO RAS optical observations
  41. GRB 211211A: AbAO optical observations
  42. GRB 211211A: GMG upper limit
  43. Chandra observation of GW170817 at ~1575 days since merger (all epochs)
  44. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  45. GRB 211211A: HCT and GIT optical follow up observations
  46. GRB 211211A: Swift/UVOT detection
  47. GRB 211211A: NOT optical spectroscopy
  48. GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
  49. GRB 211211A: MITSuME Akeno optical observation
  50. GRB 211211A: Nanshan/NEXT optical observations
  51. GRB 211211A: Enhanced Swift-XRT position
  52. GRB 211207A: Swift/UVOT Detection
  53. GRB 211211A: Swift detection of a bright burst
  54. IceCube-211208A: No significant detection in HAWC
  55. AMON NuEm-211020A: No neutrino counterpart detected with ANTARES
  56. Fermi trigger No 660736561: Global MASTER-Net observations report
  57. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  58. Fermi-LAT Gamma-ray Observations of IceCube-211208A
  59. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  60. Chandra observation of GW170817 at ~1573 days since merger (Epoch 1 of 4)
  61. GRB 211207A: Enhanced Swift-XRT position
  62. GRB 211207A: Swift detection of a burst with an optical counterpart
  63. IPN triangulation of GRB 211204C
  64. GRB 211203A: Swift detection of a burst
  65. IceCube-211125A: No significant detection in HAWC
  66. GRB 211129A: Swift/UVOT Upper Limits
  67. GRB 211129A: Fermi GBM observation
  68. GRB 211129A: Nanshan/NEXT optical upper limit
  69. GRB 211129A: Enhanced Swift-XRT position
  70. IPN triangulation of GRB 211118A
  71. GRB 211129A: MITSuME Akeno optical upper limits
  72. GRB 211129A: Swift detection of a burst
  73. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  74. GRB 211023A: Xinglong 2.16m optical observations
  75. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  76. Konus-Wind detection of GRB 211120A
  77. Chandra observations of GRB 210905A
  78. Fermi-LAT Gamma-ray Observations of IceCube-211123A
  79. IPN triangulation of GRB 211124A (short)
  80. HAWC-211123A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  81. HAWC-211123A: No neutrino counterpart detected with ANTARES
  82. Trigger_21473: Tiled Swift observations
  83. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  84. GRB 211120A: AstroSat CZTI detection
  85. GRB 211118A: AstroSat CZTI detection
  86. GRB 211023A: optical observations and photometric evidence of supernova
  87. Fermi trigger No 658971499: Global MASTER-Net observations report
  88. Fermi-LAT Gamma-ray Observations of IceCube-211116A
  89. GRB 211106A: Swift/UVOT upper limits
  90. GRB 211110A: AstroSat CZTI detection
  91. Short GRB 211106A: spectroscopy of galaxies in the field
  92. GRB 211107B: Swift-XRT afterglow detection
  93. GRB 211106A, GROND observations
  94. GRB 211106A: Swift-XRT afterglow detection
  95. GRB 211023A: SAO RAS optical observations
  96. MeerLICHT follow-up of GRB 211106A
  97. GRB 211107B: Swift ToO observations
  98. GRB 211106A: Swift-XRT observations
  99. GRB 211106A: Swift ToO observations
  100. Swift Trigger 1082569 is probably not a GRB

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