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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28059 results found.

  1. Fermi trigger No 631104264: Global MASTER-Net observations report
  2. GRB 201216C: TSHAO, Terskol, Mondy optical upper limits
  3. GRB 201227A: Chilescope optical observations, possible optical counterpart
  4. GRB 201227A: GRAWITA VST-ESO PARANAL observations
  5. GRB 201229A: AbAO optical afterglow detection, TSHAO optical upper limit
  6. GRB 201229A: SAO RAS optical observations
  7. GRB 201229A: Nanshan/NEXT optical upper limit
  8. GRB 201227A: Swift-XRT observations
  9. GRB 201229A: Swift-XRT refined Analysis
  10. GRB 201229A: Swift-BAT refined analysis
  11. GRB 201229B: BALROG localization (Fermi Trigger 630948017 / GRB 201229639)
  12. GRB 201229A: Enhanced Swift-XRT position
  13. GRB 201229A: Swift detection of a burst with a possible optical counterpart
  14. GRB 201227A: Insight-HXMT/HE detection
  15. GRB 201226A: Insight-HXMT/HE detection
  16. IPN triangulation of GRB 201227A (short)
  17. ZTF20acozryr/AT2020yxz (GRB 201103B): Maidanak optical observations
  18. GRB 201223A: AROMA-N Optical Observation
  19. GRB 201223A: Swift/UVOT Detection
  20. GRB 201223A: AbAO optical observations
  21. GRB 201223A: 1.3m DFOT and 1.04m ST optical observations
  22. GRB 201223A: Swift-XRT refined Analysis
  23. GRB 201223A: Enhanced Swift-XRT position
  24. GRB 201223A: NOT optical upper limit and NEXT powerlaw decay
  25. GRB 201223A: GROWTH-India Telescope (GIT) photometric follow-up.
  26. GRB 201223A: Mondy and Kitab optical observations
  27. GRB 201223A: iTelescope optical afterglow observations
  28. GRB 201223A: MITSuME Akeno optical observation
  29. GRB 201223A: Swift-BAT refined analysis
  30. GRB 201223A: Fermi GBM Detection
  31. GRB 201223A: Nanshan/NEXT early optical afterglow detection
  32. GRB 201223A: Swift detection of a burst with a bright optical counterpart
  33. Swift GRB201223.75: Global MASTER-Net OT detection
  34. Swift-XRT observations of Icecube 201222A
  35. IceCube-201222A: Upper limits from a search for additional neutrino events in IceCube
  36. IceCube-201222A: No significant detection in HAWC
  37. IceCube-201221A: No significant detection in HAWC
  38. GRB 201221A: REM early-time afterglow detection
  39. GRB 201221D: 3.6m DOT optical observations
  40. GRB 201221B: Insight-HXMT/HE detection
  41. IceCube-201221A: Upper limits from Insight-HXMT/HE observations
  42. GRB 201221D: SMA submm observation
  43. GRB 201221D: LCOGT upper limits
  44. GRB 201221D: Swift-BAT refined analysis
  45. Swift Trigger 1014012 (possible GRB 201221C) is likely not an astrophysical event
  46. GRB 201216A - further Swift-XRT observations
  47. Fermi-LAT Gamma-ray Observations of IceCube-201222A
  48. Fermi-LAT Gamma-ray Observations of IceCube-201221A
  49. GRB 201221D: Archival PS1 Imaging of the Putative Host Galaxy
  50. Short GRB201221D: High Redshift from OSIRIS/GTC
  51. IceCube-201222A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  52. Konus-Wind detection of GRB 201221D (short)
  53. GRB 201221D: Swift/UVOT Upper Limits
  54. GRB 201221D: Lowell Discovery Telescope afterglow observations
  55. GRB 201222B: BALROG localization (Fermi Trigger / GRB 201222461)
  56. GRB 201221D: FRAM-ORM optical limit
  57. GRB 201221D: Enhanced Swift-XRT position
  58. GRB 201221D: Nanshan/NEXT early optical upper limit
  59. GRB 201221D: candidate optical counterpart from the NOT
  60. GRB 201221A: Swift-BAT refined analysis
  61. GRB 201221D: Swift detection of a bright short burst
  62. correction to GCN 29110 - Fermi GBM Sub-Threshold Detection of GRB 201221A
  63. Fermi GBM Sub-Threshold Detection of GRB 201221A
  64. GRB 201221A: Swift/UVOT Upper Limits
  65. GRB 201221A: Swift-XRT refined Analysis
  66. Swift Trigger 1014012: possible GRB 201221C
  67. GRB 201221A: Enhanced Swift-XRT position
  68. IceCube-201221A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  69. GRB 201221A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 5.7
  70. GRB 201221A: Swift detection of a burst
  71. GRB 201209A: Mondy optical observations, afterglow confirmation
  72. GRB 201214A: TSHAO optical upper limit
  73. GRB 201214A: Swift-XRT afterglow detection
  74. GRB 201214A: 1.3m DFOT, optical upper limits
  75. IPN triangulation of GRB 201218A
  76. GRB201216C: No significant detection in HAWC
  77. GRB 201216C: Liverpool Telescope First Hour Observations
  78. GRB 201218A: BALROG localization (Fermi Trigger 629957660 / GRB 201218177)
  79. IceCube-201209A : MAXI/GSC upper limit
  80. GRB 201216C: Swift-BAT refined analysis
  81. GRB 201216C: Fermi-LAT upper limit
  82. GRB 201216C: Fermi GBM detection
  83. GRB 201216A: Fermi GBM detection
  84. GRB 201216C: Swift/UVOT Upper Limits
  85. GRB 201216A: Swift-XRT observations
  86. GRB 201216C: Enhanced Swift-XRT position
  87. GRB 201216C: VLT afterglow candidate discovery
  88. GRB 201216C: Swift-XRT observations
  89. GRB 201216A: Swift/BAT-GUANO detection and arcminute localization
  90. GRB 201214B: MITSuME Akeno optical upper limits
  91. Chandra observations of GW170817 at ~3.3 years since merger (Full report)
  92. GRB 201214B: Lowell Discovery Telescope optical observations
  93. GRB 201214B: Swift-XRT observations
  94. GRB 201209A: Insight-HXMT/HE detection
  95. IceCube-201209A: Upper limits from Insight-HXMT/HE observations
  96. GRB 201214A: Swift-XRT observations
  97. GRB 201215A: BALROG localization (Fermi Trigger 629706213 / GRB 201215266)
  98. IceCube-201209: No significant detection in HAWC
  99. Potential X-ray KN afterglow from Chandra observations of GW170817 ~3.3 years since merger (3 Epochs of 4)
  100. Long-lasting X-ray emission from GW170817 detected by Chandra

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