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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"

19715 results found.

  1. GRB 220107A: Swift/UVOT Detection
  2. GRB 220107A: MITSuME Akeno optical observation
  3. GRB 220107B: Swift-XRT afterglow detection
  4. GRB 220107A: Swift-XRT afterglow detection
  5. GRB 220107B: Fermi-LAT detection
  6. GRB 220107B: Tiled Swift observations
  7. GRB 220107A: Swift ToO observations
  8. GRB 220101A: Tautenburg observations
  9. GRB 220101A: further TNG NIR observations
  10. GRB 220101A: iTelescope optical observations
  11. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  12. GRB 211227A: Gemini South Optical Observations
  13. Alert from the HAWC Burst Monitor HAWC-220103A
  14. GRB 220101A: TNG NIR afterglow detection
  15. GRB 220101A: Tautenburg observations
  16. GRB 220101A: GMG observation (2nd epoch)
  17. GRB 211231A: AstroSat CZTI detection
  18. GRB 220101A: OASDG optical observations
  19. GRB 220101A: GMG observation
  20. GRB220101A: optical afterglow detection from Konkoly Observatory
  21. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  22. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  23. GRB 220101: Swift/UVOT Detection
  24. GRB 220101A: Enhanced Swift-XRT position
  25. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  26. IPN triangulation of GRB 211219A
  27. GRB 211229A: Swift ToO observations
  28. GRB 211227A: Swift/UVOT Upper Limits
  29. GRB 211227A: Liverpool Telescope upper limits
  30. GRB 211227A: Enhanced Swift-XRT position
  31. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  32. GRB 211221A: Swift/UVOT Upper Limits
  33. GRB 211227A: Swift detection of a burst
  34. GRB 211225B: Swift-BAT refined analysis
  35. GRB 211225A: MITSuME Akeno optical upper limits
  36. GRB 211225B: Swift detection of a burst
  37. Fermi GBM Sub-Threshold Detection of GRB 211207A
  38. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  39. GRB 211219B: AstroSat CZTI detection
  40. GRB 211219A: AstroSat CZTI detection
  41. GRB 211221A: Swift-XRT refined Analysis
  42. GRB 211218A: MITSuME Akeno optical upper limits
  43. GRB 211221A: MeerLICHT optical limits
  44. GRB 211221A: NOT optical limits
  45. GRB 211221A: Enhanced Swift-XRT position
  46. GRB 211221A: Swift detection of a burst
  47. IceCube-211216B: No significant detection in HAWC
  48. IceCube-211216A: No significant detection in HAWC
  49. GRB 211106A: XMM-Newton monitoring campaign detections
  50. Fermi-LAT Gamma-ray Observations of IceCube-211216B
  51. IceCube-211216A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  52. GRB 211211A: TNG NIR observations
  53. GRB 211211A - Gemini K-band detection
  54. GRB 211211A: SAO RAS optical observations
  55. GRB 211211A: AbAO optical observations
  56. GRB 211211A: GMG upper limit
  57. Chandra observation of GW170817 at ~1575 days since merger (all epochs)
  58. GRB 211211A: Further observations from CAFOS/2.2m CAHA
  59. GRB 211211A: HCT and GIT optical follow up observations
  60. GRB 211211A: Swift/UVOT detection
  61. GRB 211211A: NOT optical spectroscopy
  62. GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
  63. GRB 211211A: MITSuME Akeno optical observation
  64. GRB 211211A: Nanshan/NEXT optical observations
  65. GRB 211211A: Enhanced Swift-XRT position
  66. GRB 211207A: Swift/UVOT Detection
  67. GRB 211211A: Swift detection of a bright burst
  68. IceCube-211208A: No significant detection in HAWC
  69. AMON NuEm-211020A: No neutrino counterpart detected with ANTARES
  70. Fermi trigger No 660736561: Global MASTER-Net observations report
  71. GRB 211130A: MeerLICHT identification of possible afterglow candidate
  72. Fermi-LAT Gamma-ray Observations of IceCube-211208A
  73. IceCube-211208A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  74. Chandra observation of GW170817 at ~1573 days since merger (Epoch 1 of 4)
  75. GRB 211207A: Enhanced Swift-XRT position
  76. GRB 211207A: Swift detection of a burst with an optical counterpart
  77. IPN triangulation of GRB 211204C
  78. GRB 211203A: Swift detection of a burst
  79. IceCube-211125A: No significant detection in HAWC
  80. GRB 211129A: Swift/UVOT Upper Limits
  81. GRB 211129A: Fermi GBM observation
  82. GRB 211129A: Nanshan/NEXT optical upper limit
  83. GRB 211129A: Enhanced Swift-XRT position
  84. IPN triangulation of GRB 211118A
  85. GRB 211129A: MITSuME Akeno optical upper limits
  86. GRB 211129A: Swift detection of a burst
  87. IceCube-211125A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  88. GRB 211023A: Xinglong 2.16m optical observations
  89. Fermi-LAT Gamma-ray Observations of IceCube-211125A
  90. Konus-Wind detection of GRB 211120A
  91. Chandra observations of GRB 210905A
  92. Fermi-LAT Gamma-ray Observations of IceCube-211123A
  93. IPN triangulation of GRB 211124A (short)
  94. HAWC-211123A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  95. HAWC-211123A: No neutrino counterpart detected with ANTARES
  96. Trigger_21473: Tiled Swift observations
  97. GRB 211023B: LBT likely spectroscopic redshift of the host galaxy
  98. GRB 211120A: AstroSat CZTI detection
  99. GRB 211118A: AstroSat CZTI detection
  100. GRB 211023A: optical observations and photometric evidence of supernova

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