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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"

19600 results found.

  1. GRB 210112A: Swift/UVOT Detection
  2. GRB 210112A: Mondy optical observations
  3. GRB 210112A: OSN second epoch, decay
  4. NuEm-210111A : No neutrino counterpart in ANTARES
  5. GRB 210112A: Kitab a optical upper limit
  6. GRB 210104A: AROMA-N Optical Afterglow Detection
  7. GRB 210112A: Enhanced Swift-XRT position
  8. GRB 210112A: Swift detection of a burst with an optical counterpart
  9. NuEm-210111A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  10. GRB 201227A: continued Chilescope confirmation of variability of possible optical counterpart, redshift estimating
  11. GRB 210104A: SAO RAS optical observations
  12. GRB 210104A: GMG observations
  13. GRB210104A: VIRT optical transient detection.
  14. GRB 210104A: SARA-KP 0.9m Optical Afterglow Detection
  15. GRB 210102B: further Swift-XRT observations
  16. GRB 210102B: Assy optical afterglow identification
  17. GRB 210104A: iTelescope optical upper limit
  18. GW170817: HST observations at 3.4 years from merger
  19. GRB 210104A: early ATLAS detections of the bright afterglow
  20. GRB 210104B: Swift/UVOT Upper Limits
  21. GRB 210104B: Assy optical upper limit
  22. GRB 210104B: Enhanced Swift-XRT position
  23. GRB 210104A: Nanshan/NEXT optical powerlaw decay
  24. GRB 210104B: Nanshan/NEXT optical upper limit
  25. GRB 210104A: Swift/UVOT Detection
  26. GRB 210104A: Enhanced Swift-XRT position
  27. GRB 210102B: Tiled Swift observations
  28. GRB 210104B: Swift detection of a burst
  29. GRB 210104A: MITSuME Ishigaki optical observation
  30. GRB 210104A: MITSuME Akeno optical observation
  31. GRB 210104A: Swift detection of a burst with a bright optical counterpart
  32. GRB 210102C: Swift-BAT refined analysis
  33. GRB 210102B: Tiled Swift observations
  34. INTEGRAL Weak #8913: AROMA-N Optical Observation
  35. Swift Trigger 1015615 is not a GRB
  36. GRB 201229A: Swift/UVOT Detection
  37. GRB 201216C: TSHAO, Terskol, Mondy optical upper limits
  38. GRB 201227A: Chilescope optical observations, possible optical counterpart
  39. GRB 201227A: GRAWITA VST-ESO PARANAL observations
  40. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  41. GRB 201229A: SAO RAS optical observations
  42. GRB 201229A: Nanshan/NEXT optical upper limit
  43. GRB 201229A: Enhanced Swift-XRT position
  44. GRB 201229A: Swift detection of a burst with a possible optical counterpart
  45. GRB 201227A: Tiled Swift observations
  46. GRB 201227A: Swift ToO observations
  47. IPN triangulation of GRB 201227A (short)
  48. ZTF20acozryr/AT2020yxz (GRB 201103B): Maidanak optical observations
  49. GRB 201223A: AROMA-N Optical Observation
  50. GRB 201223A: Swift/UVOT Detection
  51. GRB 201223A: AbAO optical observations
  52. GRB 201223A: Enhanced Swift-XRT position
  53. GRB 201223A: NOT optical upper limit and NEXT powerlaw decay
  54. GRB 201223A: GROWTH-India Telescope (GIT) photometric follow-up.
  55. GRB 201223A: Mondy and Kitab optical observations
  56. GRB 201223A: iTelescope optical afterglow observations
  57. GRB 201223A: MITSuME Akeno optical observation
  58. GRB 201223A: Swift-BAT refined analysis
  59. GRB 201223A: Fermi GBM Detection
  60. GRB 201223A: Nanshan/NEXT early optical afterglow detection
  61. GRB 201223A: Swift detection of a burst with a bright optical counterpart
  62. Swift-XRT observations of Icecube 201222A
  63. IceCube-201222A: No significant detection in HAWC
  64. IceCube-201221A: No significant detection in HAWC
  65. GRB 201221A: REM early-time afterglow detection
  66. GRB 201221D: 3.6m DOT optical observations
  67. GRB 201221D: SMA submm observation
  68. GRB 201221D: Fermi GBM detection
  69. GRB 201216A - further Swift-XRT observations
  70. Fermi-LAT Gamma-ray Observations of IceCube-201221A
  71. IceCube-201222A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  72. GRB 201221D: Swift/UVOT Upper Limits
  73. GRB 201221D: FRAM-ORM optical limit
  74. GRB 201221D: Enhanced Swift-XRT position
  75. GRB 201221D: Nanshan/NEXT early optical upper limit
  76. GRB 201221D: candidate optical counterpart from the NOT
  77. GRB 201221D: Swift detection of a bright short burst
  78. GRB 201221A: Swift/UVOT Upper Limits
  79. Swift Trigger 1014012: possible GRB 201221C
  80. GRB 201221A: Enhanced Swift-XRT position
  81. IceCube-201221A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  82. GRB 201221A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 5.7
  83. GRB 201221A: Swift detection of a burst
  84. GRB 201209A: Mondy optical observations, afterglow confirmation
  85. GRB 201214A: TSHAO optical upper limit
  86. GRB 201214A: Swift-XRT afterglow detection
  87. GRB 201214A: 1.3m DFOT, optical upper limits
  88. IPN triangulation of GRB 201218A
  89. GRB201216C: No significant detection in HAWC
  90. GRB 201216C: Liverpool Telescope First Hour Observations
  91. GRB 201216C: Fermi-LAT upper limit
  92. GRB 201216C: AstroSat CZTI detection
  93. GRB 201216C: Swift/UVOT Upper Limits
  94. GRB 201216A: Swift-XRT observations
  95. GRB 201216C: Enhanced Swift-XRT position
  96. GRB 201216C: VLT afterglow candidate discovery
  97. GRB 201216A: Swift ToO observations
  98. GRB 201216C: Swift-XRT observations
  99. GRB 201214B: MITSuME Akeno optical upper limits
  100. Chandra observations of GW170817 at ~3.3 years since merger (Full report)

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