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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"

19089 results found.

  1. Konus-Wind observation of GRB 170208B
  2. Konus-Wind observation of GRB 170208A
  3. GRB 170208B: GROND observations
  4. GRB 170208B: NOT upper limits
  5. GRB 170208B: Etelman observatory optical observations
  6. GRB 170208B: Enhanced Swift-XRT position
  7. GRB 170208A: Enhanced Swift-XRT position
  8. GRB 170208B: Swift detection of a burst
  9. GRB 170208A: Swift detection of a burst
  10. IPN Triangulation of GRB 170207A (long/very bright)
  11. GRB 170206B: Swift/UVOT Upper Limits
  12. GRB 170206B: Swift-XRT refined Analysis
  13. GRB 170206B: Enhanced Swift-XRT position
  14. GRB 170206B: Swift detection of a burst
  15. GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
  16. GRB 170205A: NOT afterglow observations
  17. GRB 170205A: Enhanced Swift-XRT position
  18. GRB 170205A: RATIR Optical and NIR Observations
  19. GRB 170202A: SMARTS optical/IR afterglow observations
  20. GRB 170205A: Swift detection of a burst with an optical counterpart
  21. GRB 170202A: Zadko observatory - Gingin optical observations
  22. GRB 170202A: Etelman Observatory optical observations
  23. GRB 170202A: RATIR Optical and NIR Observations
  24. GRB 170202A: SQUEAN Observation
  25. GRB 170202A: T100 observations
  26. GRB 170202A: Swift/UVOT Detection
  27. GRB 170202A: Enhanced Swift-XRT position
  28. GRB 170202A: NOT afterglow observations
  29. GRB 170202A: Zadko observatory - Gingin optical observations
  30. GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
  31. GRB 170202A: Mini-MegaTORTORA upper limits
  32. GRB 170202A: Swift detection of a burst with an optical afterglow
  33. GRB 170131A: Swift/UVOT Upper Limits
  34. GRB 170131A: Swift ToO observations
  35. GRB 170127B: Swift-BAT refined analysis
  36. GRB 170127C: Swift-XRT observations
  37. GRB 170127A: GROND Upper limits
  38. GRB 170124A: CALET Gamma-Ray Burst Monitor detection
  39. GRB 170127B: Swift/UVOT Upper Limits
  40. GRB 170127A: Swift/UVOT Upper Limits
  41. GRB 170127B: Enhanced Swift-XRT position
  42. GRB 170127B: NOT r-band upper limits
  43. GRB 170127A: Enhanced Swift-XRT position
  44. GRB 170127C: Tiled Swift observations
  45. GRB 170127C: Fermi-LAT detection
  46. LIGO/Virgo G270580: HAWC follow-up observations
  47. GRB 170127B: Swift detection of a short burst
  48. GRB 170127A: Swift detection of a burst
  49. GRB 170126A: Swift/UVOT Detection of a Fading Afterglow
  50. GRB 170126A: Enhanced Swift-XRT position
  51. GRB 170126A: Swift detection of a burst with an optical counterpart
  52. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  53. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  54. GRB 170121B: AbAO optical observations
  55. LIGO/Virgo G270580: CALET Observations
  56. GRB 170121B: Swift-XRT and UVOT observations
  57. GRB 170121B: Swift ToO observations
  58. LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
  59. LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
  60. LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
  61. LIGO/Virgo G270580: Swift/BAT data search
  62. LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
  63. LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
  64. LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
  65. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  66. LIGO/Virgo G270580: AGILE MCAL and Super-AGILE Observations
  67. LIGO/Virgo G270580 ANTARES search
  68. GRB 170117A: Swift/UVOT Upper Limits
  69. GRB 170117A: Swift-XRT observations
  70. GRB 170117A: Swift ToO observations
  71. GRB 170115A : AbAO optical upper limit
  72. GRB 170115A: Swift/UVOT Upper Limits
  73. GRB 170112A : AbAO optical observations
  74. GRB 170115B: Tiled Swift observations
  75. GRB 170115A: Enhanced Swift-XRT position
  76. GRB 170115A: Swift detection of a burst
  77. GRB 170113A: GROND afterglow observations
  78. GRB 170113A: Swift/UVOT Observations
  79. GRB 170112A: Swift/UVOT Upper Limits
  80. GRB 170113A: Enhanced Swift-XRT position
  81. GRB 170113A: Swift detection of a burst with an optical counterpart
  82. LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
  83. GRB 170112A: RATIR Optical and NIR Observations
  84. GRB 170112A: Swift-BAT refined analysis
  85. GRB 161219B: afterglow and SN2016jca optical observations
  86. GRB 170111A: Swift/UVOT Upper Limits
  87. GRB 170112A: Swift-XRT observations
  88. GRB 170112A: REM optical/NIR observations
  89. GRB 170112A: Swift detection of a short burst
  90. GRB170111A: REM optical/NIR observations
  91. LIGO/Virgo G268556: Early SWASP limits of ATLAS17aeu
  92. LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
  93. GRB 170111A: Enhanced Swift-XRT position
  94. GRB 170111A: Swift detection of a burst
  95. LIGO/Virgo G268556: Swift/BAT data search
  96. LIGO/Virgo G268556: Lijiang Observatory GMG Telescope Upper Limit on ATLAS17aeu
  97. LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
  98. LIGO/Virgo G268556/GW170104: TNG observations of ATLAS17aeu
  99. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  100. LIGO/Virgo G268556: GWAC_F60B (60cm) follow-up two events of EWE001 and EWE002

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