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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.

Advanced Search Examples (click to copy):

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

19041 results found.

  1. GRB151212A: Swift/UVOT observations
  2. GRB 151212A: GROND Optical Afterglow Candidate
  3. GRB 151212A: Tiled Swift observations
  4. GRB 151210A: Swift/UVOT Upper Limits
  5. GRB 151210A: Enhanced Swift-XRT position
  6. GRB 151210A: GROND Afterglow Confirmation
  7. GRB 151210A: Optical afterglow candidate from LCOGT-Cerro Tololo
  8. GRB 151210A: Swift detection of a burst
  9. GRB 151205C: Optical follow-up observations at Kiso
  10. GRB 151205A: Khureltogot upper limit
  11. GRB 151205B: Deep GROND Upper limits
  12. GRB 130831A: MASTER early OT detection and LC
  13. GRB 151205B: further Swift-XRT observations
  14. GRB 151205C: Swift-XRT observations
  15. GRB 151205C: Tiled Swift observations
  16. GRB 151205A: Garching Telescope Upper Limit
  17. GRB151205B: Initial UVOT observations
  18. GRB 151205B: Swift-XRT observations
  19. GRB 151205A: Swift/UVOT Upper Limits
  20. GRB 151205A: Enhanced Swift-XRT position
  21. GRB 151205A: Swift detection of a burst
  22. GRB 151127A iTelescope observation
  23. LIGO/Virgo G184098: Results of of 2nd epoch of ASKAP follow-up
  24. GRB 151122A: Further Swift-XRT observations, no afterglow detected.
  25. GRB 151127A: Swift/UVOT Upper Limits
  26. GRB 151127A: Swift-BAT refined analysis
  27. GRB 151127A: Enhanced Swift-XRT position
  28. GRB 151127A: GROND K-band upper limit
  29. GRB 151127A: LCOGT-SSO optical upper limits
  30. GRB 151127A: Swift detection of a short burst
  31. GRB 151118A iTelescope observation
  32. GRB 151122A: Swift/UVOT Observations
  33. GRB 151122A: Fermi GBM detection
  34. GRB 151122A: Swift ToO observations
  35. Swift-BAT refined analysis of trigger 664624 from SGR J1819-1600
  36. Swift Trigger 664610: is unlikely a GRB
  37. GRB 151118A: AAO optical upper limit
  38. GRB 151120A: Swift ToO observations
  39. GRB 151120A: GROND optical/NIR afterglow
  40. GRB 151120A: A long GRB detected by INTEGRAL
  41. LIGO/Virgo G194575: Fermi GBM Observations
  42. GRB 151118A: Early optical limit from pt5m, La Palma
  43. GRB 151118A: ISON-NM early optical limit
  44. GRB 151027A: SAO RAS and Mt. Terskol observations
  45. GRB 151118A: Swift/UVOT Upper Limits
  46. GRB 151118A: Enhanced Swift-XRT position
  47. GRB 151118A: Optical observations from OSN
  48. GRB 151118A: Swift detection of a burst
  49. GRB151027A; Optical observations
  50. GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
  51. GRB 151114A: Swift/UVOT Detection
  52. GRB 151114A: Enhanced Swift-XRT position
  53. GRB 151114A: Swift detection of a burst with an optical counterpart
  54. GRB 151111A: GROND confirmation of the afterglow and photometric redshift estimate
  55. GRB 151112A: Swift/UVOT Upper Limits
  56. GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
  57. GRB 151112A: Enhanced Swift-XRT position
  58. GRB 151112A: initial UVOT observations
  59. GRB 151112A: Swift-XRT observations
  60. GRB 151111A: Swift/UVOT upper limits
  61. Swift-BAT trigger 663164 is not a burst.
  62. GRB 151111A: GROND marginal detection of a afterglow candidate
  63. GRB 151111A: Swift-XRT refined Analysis
  64. GRB 151111A: Fermi GBM observation
  65. GRB 151111A: Enhanced Swift-XRT position
  66. GRB 151111A: Swift detection of a burst
  67. GRB 151107B: Mini-MegaTORTORA limits on simultaneous optical emission
  68. GRB 151107A: Further investigation of the source nature
  69. GRB 151027A: Mt. Terskol observatory optical observation
  70. LIGO/Virgo G194575: MAXI/GSC further analysis
  71. GRB 150910A: CrAO optical observations
  72. GRB 151027A: the missing GeV component
  73. GRB 151031A: GROND observation
  74. GRB 151027B: ATCA radio detection
  75. GRB 151031A
  76. GRB 151031A: Swift/UVOT Detection
  77. GRB 151027B: RATIR Late-Time Upper Limits
  78. GRB 151031A: Enhanced Swift-XRT position
  79. GRB 151031A: VLT/X-shooter optical counterpart and redshift
  80. GRB 151031A: Swift detection of a burst
  81. GRB 151029A: MITSuME Ishigakijima upper limits
  82. GRB 151027A: Optical counterpart detection
  83. GRB 151029A: Swift/UVOT Detection
  84. GRB 151029A: Enhanced Swift-XRT position
  85. GRB 151029A: GROND afterglow observations
  86. GRB 151027A: SAO RAS optical observations
  87. GRB 151027A: NOT optical and NIR observations
  88. GRB 151027A: T100 observations
  89. GRB 151027B: Swift/UVOT Upper Limits
  90. GRB 151027A: continued GMG observation
  91. GRB 151027B: RATIR Observations
  92. GRB 151027B: Swift-XRT refined Analysis
  93. GRB 151027B: GROND Optical/NIR Afterglow Detection
  94. GRB 151027B: Enhanced Swift-XRT position
  95. GRB 151027A: UVOT Observations
  96. GRB 151027B: NOT optical afterglow candidate
  97. GRB 151027B: Swift detection of its 1000-th burst
  98. LIGO/Virgo O1 extended until January 12
  99. GRB 151027A: Early RAPTOR Observations
  100. GRB 151027A: GMG observation

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