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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"

43674 results found.

  1. GRB 141221A: Fermi GBM observation
  2. GRB 141221A: Swift-XRT refined Analysis
  3. GRB 141221A: Swift-BAT refined analysis
  4. GRB141221A: GROND Afterglow Detection
  5. GRB 141221A: Enhanced Swift-XRT position
  6. GRB 141221A: Skynet PROMPT-CTIO observations of the optical afterglow
  7. GRB 141221A: LCOGT-McDonald optical afterglow observations
  8. GRB141221A: REM afterglow
  9. Konus-Wind observation of GRB 141220A
  10. GRB 141221A: Swift detection of a burst with an optical counterpart
  11. GRB 141220A: Fermi GBM observation
  12. GRB 141220A: Swift-XRT refined Analysis
  13. GRB 141220A: Swift-BAT refined analysis
  14. GRB 141220A: Swift/UVOT Detection
  15. GRB 141220A: Photometry from OSIRIS/GTC
  16. GRB 141220A: LT optical afterglow observations
  17. GRB 141220A: Redshift from OSIRIS at the 10.4m GTC
  18. GRB141220A: 1.23m CAHA I-band observations
  19. GRB 141220A: Swift detection of a burst with an optical afterglow
  20. Fermi Gamma-ray Burst Monitor trigger 440728127 / 141220020 is not a GRB
  21. IPN Triangulation of GRB 141207A
  22. GRB 141207A: Suzaku WAM observation of the prompt emission
  23. GRB 141202A: Suzaku WAM observation of the prompt emission
  24. GRB 141121A: Keck observations
  25. GRB 141215A: Swift-XRT observations
  26. GRB 141215A: Fermi GBM detection
  27. GRB 141215A Tiled Swift observations
  28. Konus-Wind observation of GRB 141215A
  29. IPN Triangulation of GRB 141215A (long/intense)
  30. GRB 141212A iTelescope observation
  31. GRB 141212A: Zadko observatory - Gingin optical observations
  32. Konus-Wind observation of GRB 141212B
  33. GRB 141212B: Swift-XRT refined Analysis
  34. GRB 141212A: VLA upper limit
  35. GRB 141212A: Gemini-N spectroscopy and photometry
  36. GRB 141212B: Swift-BAT refined analysis
  37. GRB 141212A: Swift-BAT refined analysis
  38. GRB 141212B: Enhanced Swift-XRT position
  39. Swift detection of 4U 1700+24 (= V934 Her)
  40. GRB 141212A: Swift-XRT refined Analysis
  41. GRB 141212A: extended object within the XRT error circle
  42. GRB 141212A: Khureltogot optical upper limit
  43. GRB 141212A: 1.23m CAHA I-band observations
  44. GRB 141212B: initial Swift/UVOT observations
  45. GRB 141212B: Swift/XRT preliminary localization
  46. GRB 141212A: Enhanced Swift-XRT position
  47. GRB 141212A: MASTER early optical observations
  48. GRB 141212A: Skynet R-COP Observations
  49. GRB 141212B: Swift detection of a burst
  50. GRB 141212A: Swift detection of a short burst
  51. GRB 141207A: Swift-XRT afterglow candidate detection
  52. GRB 141121A: further VLA observations
  53. Konus-Wind observation of GRB 141207A
  54. GRB141208.63: MASTER OT Detection During the Fermi Error Box inspection
  55. GRB141202A: Discovery Channel Telescope Optical Observations
  56. GRB141207A: Discovery Channel Telescope Optical Observations
  57. GRB 141207A: Swift-UVOT Observations
  58. GRB 141207A: Fermi GBM detection
  59. GRB 141207A: Swift-XRT observations
  60. Konus-Wind observation of GRB 141130A
  61. GRB 141207A Tiled Swift observations
  62. GRB 141207A: Fermi-LAT Detection
  63. GRB141121A: Discovery Channel Telescope Optical Observations
  64. GRB 141205A: Fermi GBM detection
  65. GRB 141205A: Nanshan optical upper limit
  66. GRB 141205A: XRT observations
  67. GRB 141205A Swift-BAT refined analysis
  68. GRB 141202A: Swift/UVOT Detection of a Variable Source Near the IPN Error Box
  69. GRB 141121A: Mondy optical observations
  70. GRB 141205A Short hard GRB found in ground analysis of BAT data
  71. Konus-Wind observation of GRB 141202A
  72. GRB 141130A: Mondy optical observations
  73. GRB 141202A: Swift XRT observations
  74. GRB 141202A: Fermi GBM Detection
  75. GRB 141202A Tiled Swift observations
  76. IPN Triangulation of GRB 141202A (short/hard)
  77. GRB 141130A: Mondy optical light curve
  78. GRB 141030A: Nanshan very early optical observations
  79. GRB 141121A: Continued RATIR Optical Observations
  80. GRB 141130A: Swift-BAT refined analysis
  81. GRB 141130A: Swift/UVOT Detection
  82. GRB 141130A: Swift-XRT refined Analysis
  83. GRB 141121A: VLA radio detection
  84. GRB 141130A: Enhanced Swift-XRT position
  85. GRB 141130A: Nanshan optical observations
  86. GRB 141130A: Mondy optical observations
  87. GRB 141130A: Swift detection of a burst with an optical counterpart
  88. GRB 141121A: Continued RATIR Optical Observations
  89. GRB 141121A: Mondy optical observations
  90. GRB 141121A: TSHAO optical observations
  91. GRB 141121A: Continued RATIR Optical Observations
  92. GRB 141121A: RATIR Optical Observations - Errata for GCN 17105
  93. GRB 141121A: Khureltogot optical observations
  94. IPN Triangulation of GRB 141121A (initial episode)
  95. GRB 141121A: Mondy optical observations
  96. GRB 141121A: SPI-ACS/INTEGRAL observations
  97. GRB 141121A: RATIR Optical and NIR Observations
  98. Konus-Wind observation of GRB 141121A
  99. IPN Triangulation of GRB 141125A (short/hard)
  100. GRB 141121A: three epochs of SAO RAS optical observations

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