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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"

37512 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 440728127 / 141220020 is not a GRB
  2. IPN Triangulation of GRB 141207A
  3. GRB 141207A: Suzaku WAM observation of the prompt emission
  4. GRB 141202A: Suzaku WAM observation of the prompt emission
  5. GRB 141121A: Keck observations
  6. GRB 141215A: Swift-XRT observations
  7. GRB 141215A: Fermi GBM detection
  8. GRB 141215A Tiled Swift observations
  9. Konus-Wind observation of GRB 141215A
  10. IPN Triangulation of GRB 141215A (long/intense)
  11. GRB 141212A iTelescope observation
  12. GRB 141212A: Zadko observatory - Gingin optical observations
  13. GRB 141212B: MITSuME Akeno upper limits
  14. Konus-Wind observation of GRB 141212B
  15. GRB 141212B: Swift-XRT refined Analysis
  16. GRB 141212A: Swift/UVOT Upper Limits
  17. GRB 141212B: Swift/UVOT Upper Limits
  18. GRB 141212A: VLA upper limit
  19. GRB 141212A: Gemini-N spectroscopy and photometry
  20. GRB 141212B: Swift-BAT refined analysis
  21. GRB 141212A: Swift-BAT refined analysis
  22. GRB 141212B: Enhanced Swift-XRT position
  23. GRB 141212A: MITSuME Okayama upper limits
  24. GRB 141212A: Swift-XRT refined Analysis
  25. GRB 141212A: extended object within the XRT error circle
  26. GRB141212A: xinglong TNT upper limit
  27. GRB 141212A: Khureltogot optical upper limit
  28. GRB 141212A: 1.23m CAHA I-band observations
  29. GRB 141212B: initial Swift/UVOT observations
  30. GRB 141212B: Swift/XRT preliminary localization
  31. GRB 141212A: Enhanced Swift-XRT position
  32. GRB 141212A: Correction to GCN 17162
  33. GRB 141212A: MASTER early optical observations
  34. GRB 141212A: Skynet R-COP Observations
  35. GRB 141212A: MITSuME Akeno upper limits
  36. GRB 141212B: Swift detection of a burst
  37. GRB 141212A: Swift detection of a short burst
  38. GRB 141207A: Swift-XRT afterglow candidate detection
  39. GRB 141121A: further VLA observations
  40. Konus-Wind observation of GRB 141207A
  41. GRB141208.63: MASTER OT Detection During the Fermi Error Box inspection
  42. GRB141207A: Discovery Channel Telescope Optical Observations
  43. GRB 141207A: Swift-UVOT Observations
  44. GRB 141207A: Fermi GBM detection
  45. GRB 141207A: Swift-XRT observations
  46. Konus-Wind observation of GRB 141130A
  47. GRB 141207A Tiled Swift observations
  48. GRB 141207A: Fermi-LAT Detection
  49. GRB141121A: Discovery Channel Telescope Optical Observations
  50. GRB 141205A: Swift/UVOT Upper Limits
  51. GRB 141205A: Fermi GBM detection
  52. GRB 141205A: Nanshan optical upper limit
  53. GRB 141205A: XRT observations
  54. GRB 141205A Swift-BAT refined analysis
  55. GRB 141202A: Swift/UVOT Detection of a Variable Source Near the IPN Error Box
  56. GRB 141121A: Mondy optical observations
  57. GRB 141205A Short hard GRB found in ground analysis of BAT data
  58. Konus-Wind observation of GRB 141202A
  59. GRB 141130A: Mondy optical observations
  60. GRB 141202A: Swift XRT observations
  61. GRB 141202A: Fermi GBM Detection
  62. GRB 141202A Tiled Swift observations
  63. IPN Triangulation of GRB 141202A (short/hard)
  64. GRB 141130A: Mondy optical light curve
  65. GRB 141030A: Nanshan very early optical observations
  66. GRB 141121A: Continued RATIR Optical Observations
  67. GRB 141130A: Swift-BAT refined analysis
  68. GRB 141130A: Swift/UVOT Detection
  69. GRB 141130A: Swift-XRT refined Analysis
  70. GRB 141121A: VLA radio detection
  71. GRB 141130A: Enhanced Swift-XRT position
  72. GRB 141130A: Nanshan optical observations
  73. GRB 141130A: Mondy optical observations
  74. GRB 141130A: Swift detection of a burst with an optical counterpart
  75. GRB 141121A: Continued RATIR Optical Observations
  76. GRB 141121A: Mondy optical observations
  77. GRB 141121A: TSHAO optical observations
  78. GRB 141121A: Continued RATIR Optical Observations
  79. GRB 141121A: RATIR Optical Observations - Errata for GCN 17105
  80. GRB 141121A: MITSuME Ishigakijima Optical Observation after 7 days
  81. GRB 141121A: Khureltogot optical observations
  82. IPN Triangulation of GRB 141121A (initial episode)
  83. GRB 141121A: Mondy optical observations
  84. GRB 141121A: SPI-ACS/INTEGRAL observations
  85. GRB 141121A: RATIR Optical and NIR Observations
  86. Konus-Wind observation of GRB 141121A
  87. IPN Triangulation of GRB 141125A (short/hard)
  88. GRB 141121A: three epochs of SAO RAS optical observations
  89. GRB 141121A: Continued RATIR Optical Observations
  90. GRB 141121A: WSRT radio detection
  91. GRB 141121A: TSHAO optical observations
  92. GRB 141121A: Continued Mondy optical observations
  93. GRB 141121A: Continued RATIR Optical Observations
  94. GRB 141121A: RATIR Optical Observations - Steeper Fading
  95. GRB 141121A: AMI 15 GHz detection
  96. GRB 141121A: MITSuME Ishigakijima Optical Observation after 3 days
  97. GRB 141124A​: iPTF upper limits​
  98. GRB 141121A: RATIR Optical Observations - Fading Again
  99. GRB141124A: MASTER Detection of New Flare of QSO NVSS J075043+790917 During the Fermi Error Box inspection
  100. GRB 141118A: Fermi GBM Detection

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