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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"

19551 results found.

  1. GRB 180325A: VLT/X-shooter spectroscopic observations
  2. GRB 180325A: Swift/UVOT Detection
  3. GRB 180325A: GROND observations
  4. GRB 180325A: TAROT Calern observatory optical observations
  5. GRB 180325A: D50 early optical follow-up
  6. GRB 180325A: Enhanced Swift-XRT position
  7. GRB 180325A: Optical Photometry with SLKT
  8. GRB 180325A: RATIR Optical Observations
  9. GRB 180325A: prompt REM optical/NIR detection
  10. GRB 180325A: NOT redshift
  11. GRB 180325A: Swift detection of a burst with an optical counterpart
  12. GRB 180324A: Swift/UVOT Upper Limits
  13. GRB 180324A: Enhanced Swift-XRT position
  14. GRB 180324A: RATIR Optical Observations and Possible Afterglow Detection
  15. GRB 180324A: Swift detection of a burst
  16. IPN Triangulation of GRB 180317A (short/hard)
  17. GRB 180316A: RATIR Optical Observations
  18. GRB 180316A: TSHAO optical observations
  19. GRB 180316A: RATIR Optical Observations, Possible Re-brightening
  20. GRB 180316A: Swift/UVOT Detection
  21. GRB 180316A: RATIR Optical Observations
  22. GRB 180316A: Enhanced Swift-XRT position
  23. GRB 180316A: LCO Cerro Tololo observations
  24. GROND observations of GRB 180316A
  25. GRB 180316A: Swift detection of a burst
  26. GRB 180314B: RATIR Optical Observations
  27. GRB 180314B: Zeiss-1000/CrAO optical upper limit
  28. GRB 180314B: Swift/UVOT Upper Limits
  29. GRB 180314B: Enhanced Swift-XRT position
  30. GRB 180314B: Swift detection of a burst
  31. Swift Trigger on MAXI J1820+070
  32. GRB 180314A: TAROT La Silla observatory optical observations
  33. GRB 180314A: LCO Siding Springs observations
  34. GRB 180314A: Swift/UVOT Detection
  35. GRB 180314A: REM optical/NIR observations
  36. GRB 180314A: MASTER-Net OT dtetction
  37. GRB 180314A: Enhanced Swift-XRT position
  38. GRB180314A: GROND detection of the afterglow
  39. GRB 180314A: Swift detection of a burst with an optical counterpart
  40. GRB 180311A: Swift/UVOT Upper Limits
  41. MAXI J1820+070: Swift/UVOT counterpart correction
  42. Swift detection of MAXI J1820+070
  43. GRB 180311A: Enhanced Swift-XRT position
  44. GRB 180311A: Swift detection of a burst
  45. GRB 180305A CALET Gamma-Ray Burst Monitor detection
  46. GRB 180305A: RATIR Optical Observations
  47. GRB 180305A: Swift/UVOT Upper Limits
  48. GRB 180305A: Mondy optical observations
  49. GRB 180305A: Swift-XRT afterglow detection
  50. GRB 180305A: RATIR Optical Afterglow Candidate
  51. GRB 180305A: Swift ToO observations
  52. GRB 180305A: Fermi-LAT detection
  53. GRB 180224A: Swift/UVOT Detection
  54. GRB 180224A: OASDG optical observations
  55. IPN Triangulation of GRB 180223A (long)
  56. GRB 180210A: Insight-HXMT/HE observation
  57. Swift Trigger 811686 is probably not an astrophysical source.
  58. GRB 180224A: AbAO optical observations
  59. GRB 180224A: RATIR Optical Observations
  60. GRB 180224A: Enhanced Swift-XRT position
  61. GRB 180224A: Swift detection of a burst with an optical counterpart
  62. MAXI J1813-095 source: AbAO optical observations
  63. GRB 180222A: Swift/UVOT Upper Limits
  64. GRB 180222A: Swift-BAT refined analysis
  65. GRB 180222A: Enhanced Swift-XRT position
  66. GRB 180222A: Swift detection of a burst
  67. Swift trigger 811074 (possible GRB 180221A): Swift refined analysis
  68. Swift Trigger 811167: Detection of MAXI J1813-095
  69. GRB 180205A: Mondy optical observations
  70. IPN Triangulation of GRB 180218A (long/bright)
  71. GRB 180204A: 15 GHz upper limits from AMI
  72. Konus-Wind observation of GRB 180210A
  73. GRB 180205A: SEDM Observations
  74. GRB 180210A: Swift-XRT afterglow detection
  75. GRB 180210A: Tiled Swift observations
  76. GRB 180205A: BAO optical observations
  77. GRB 180210A: Swift ToO observations
  78. Trigger 809374: Swift detection of a possible non-burst faint source
  79. Trigger 809217: Swift trigger on RS CVn Star HD 8357
  80. GRB180205A: Optical observations with DOAO 1m telescope
  81. GRB 180205A: AbAO optical observations
  82. GRB 180205A: Swift/UVOT Detection
  83. GRB 180205A: Nanshan-1m optical observations
  84. GRB 180205A: Swift-XRT refined Analysis
  85. GRB 180205A: Further GROND Observations reveal Afterglow is still bright
  86. GRB 180205A: Nickel telescope optical observations
  87. Swift Trigger on AXP CXOU J164710.2-455216/PSR J1647-4552
  88. GRB 180205A: Mondy optical observations
  89. GRB 180205A: GROND detection of the NIR/optical afterglow
  90. GRB 180205A: Swift detection of a burst with a bright optical counterpart
  91. GRB 180204A: Swift/UVOT Upper Limits
  92. GRB 180204A: Enhanced Swift-XRT position
  93. GRB 180204A: Swift-XRT refined Analysis
  94. GRB 180204A: Swift detection of a short burst
  95. GW170817/GRB170817A: Preliminary results of Chandra monitoring
  96. LIGO/Virgo GW170817: Chandra X-ray Emission Continues to Rise ~156 Days Post-Merger
  97. GRB 180115A: SEDM Observations
  98. GRB 180111A AROMA-N optical observation
  99. IPN Triangulation of GRB 180113C
  100. GRB 180115A: NOT detection of optical counterpart

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