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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"

28255 results found.

  1. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  2. GRB 201229A: SAO RAS optical observations
  3. GRB 201229A: Nanshan/NEXT optical upper limit
  4. GRB 201227A: Swift-XRT observations
  5. GRB 201229A: Swift-XRT refined Analysis
  6. GRB 201229A: Swift-BAT refined analysis
  7. GRB 201229B: BALROG localization (Fermi Trigger 630948017 / GRB 201229639)
  8. GRB 201229A: Enhanced Swift-XRT position
  9. GRB 201229A: Swift detection of a burst with a possible optical counterpart
  10. GRB 201227A: Insight-HXMT/HE detection
  11. GRB 201226A: Insight-HXMT/HE detection
  12. IPN triangulation of GRB 201227A (short)
  13. ZTF20acozryr/AT2020yxz (GRB 201103B): Maidanak optical observations
  14. GRB 201223A: AROMA-N Optical Observation
  15. GRB 201223A: Swift/UVOT Detection
  16. GRB 201223A: AbAO optical observations
  17. GRB 201223A: 1.3m DFOT and 1.04m ST optical observations
  18. GRB 201223A: Swift-XRT refined Analysis
  19. GRB 201223A: Enhanced Swift-XRT position
  20. GRB 201223A: NOT optical upper limit and NEXT powerlaw decay
  21. GRB 201223A: GROWTH-India Telescope (GIT) photometric follow-up.
  22. GRB 201223A: Mondy and Kitab optical observations
  23. GRB 201223A: iTelescope optical afterglow observations
  24. GRB 201223A: MITSuME Akeno optical observation
  25. GRB 201223A: Swift-BAT refined analysis
  26. GRB 201223A: Fermi GBM Detection
  27. GRB 201223A: Nanshan/NEXT early optical afterglow detection
  28. GRB 201223A: Swift detection of a burst with a bright optical counterpart
  29. Swift GRB201223.75: Global MASTER-Net OT detection
  30. Swift-XRT observations of Icecube 201222A
  31. IceCube-201222A: Upper limits from a search for additional neutrino events in IceCube
  32. IceCube-201222A: No significant detection in HAWC
  33. IceCube-201221A: No significant detection in HAWC
  34. GRB 201221A: REM early-time afterglow detection
  35. GRB 201221D: 3.6m DOT optical observations
  36. GRB 201221B: Insight-HXMT/HE detection
  37. IceCube-201221A: Upper limits from Insight-HXMT/HE observations
  38. GRB 201221D: SMA submm observation
  39. GRB 201221D: LCOGT upper limits
  40. GRB 201221D: Swift-BAT refined analysis
  41. Swift Trigger 1014012 (possible GRB 201221C) is likely not an astrophysical event
  42. GRB 201216A - further Swift-XRT observations
  43. Fermi-LAT Gamma-ray Observations of IceCube-201222A
  44. Fermi-LAT Gamma-ray Observations of IceCube-201221A
  45. GRB 201221D: Archival PS1 Imaging of the Putative Host Galaxy
  46. Short GRB201221D: High Redshift from OSIRIS/GTC
  47. IceCube-201222A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  48. Konus-Wind detection of GRB 201221D (short)
  49. GRB 201221D: Swift/UVOT Upper Limits
  50. GRB 201221D: Lowell Discovery Telescope afterglow observations
  51. GRB 201222B: BALROG localization (Fermi Trigger / GRB 201222461)
  52. GRB 201221D: FRAM-ORM optical limit
  53. GRB 201221D: Enhanced Swift-XRT position
  54. GRB 201221D: Nanshan/NEXT early optical upper limit
  55. GRB 201221D: candidate optical counterpart from the NOT
  56. GRB 201221A: Swift-BAT refined analysis
  57. GRB 201221D: Swift detection of a bright short burst
  58. correction to GCN 29110 - Fermi GBM Sub-Threshold Detection of GRB 201221A
  59. Fermi GBM Sub-Threshold Detection of GRB 201221A
  60. GRB 201221A: Swift/UVOT Upper Limits
  61. GRB 201221A: Swift-XRT refined Analysis
  62. Swift Trigger 1014012: possible GRB 201221C
  63. GRB 201221A: Enhanced Swift-XRT position
  64. IceCube-201221A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  65. GRB 201221A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 5.7
  66. GRB 201221A: Swift detection of a burst
  67. GRB 201209A: Mondy optical observations, afterglow confirmation
  68. GRB 201214A: TSHAO optical upper limit
  69. GRB 201214A: Swift-XRT afterglow detection
  70. GRB 201214A: 1.3m DFOT, optical upper limits
  71. IPN triangulation of GRB 201218A
  72. GRB201216C: No significant detection in HAWC
  73. GRB 201216C: Liverpool Telescope First Hour Observations
  74. GRB 201218A: BALROG localization (Fermi Trigger 629957660 / GRB 201218177)
  75. IceCube-201209A : MAXI/GSC upper limit
  76. GRB 201216C: Swift-BAT refined analysis
  77. GRB 201216C: Fermi-LAT upper limit
  78. GRB 201216C: Fermi GBM detection
  79. GRB 201216A: Fermi GBM detection
  80. GRB 201216C: Swift/UVOT Upper Limits
  81. GRB 201216A: Swift-XRT observations
  82. GRB 201216C: Enhanced Swift-XRT position
  83. GRB 201216C: VLT afterglow candidate discovery
  84. GRB 201216C: Swift-XRT observations
  85. GRB 201216A: Swift/BAT-GUANO detection and arcminute localization
  86. GRB 201214B: MITSuME Akeno optical upper limits
  87. Chandra observations of GW170817 at ~3.3 years since merger (Full report)
  88. GRB 201214B: Lowell Discovery Telescope optical observations
  89. GRB 201214B: Swift-XRT observations
  90. GRB 201209A: Insight-HXMT/HE detection
  91. IceCube-201209A: Upper limits from Insight-HXMT/HE observations
  92. GRB 201214A: Swift-XRT observations
  93. GRB 201215A: BALROG localization (Fermi Trigger 629706213 / GRB 201215266)
  94. IceCube-201209: No significant detection in HAWC
  95. Potential X-ray KN afterglow from Chandra observations of GW170817 ~3.3 years since merger (3 Epochs of 4)
  96. Long-lasting X-ray emission from GW170817 detected by Chandra
  97. GRB 201214A: A long GRB detected by INTEGRAL
  98. Integral GRB201214.26: Global MASTER-Net observations report
  99. GRB 201015A: optical observations and supernova identification
  100. GRB 201203A: Zeiss-1000 (Koshka observatory) optical upper limit

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