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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"
  1. GRB 140713A: Swift-XRT refined Analysis
  2. GRB 140713A: Swift/UVOT Upper Limits
  3. GRB 140713A: NOT upper limits
  4. GRB 140713A : Xinglong TNT upper limit
  5. GRB 140713A: Enhanced Swift-XRT position
  6. GRB 140713A: Swift-BAT refined analysis
  7. GRB 140713A: T100 observations
  8. GRB 140710A: iTelescope.Net T11 Optical Observation
  9. GRB 140713A: Swift detection of a burst
  10. Swift Trigger 604111 is not a GRB
  11. GRB 140710B: Fermi GBM detection
  12. GRB 140710B: improved INTEGRAL position
  13. Fermi GBM Observations of SGR 1935+2154
  14. GRB 140710B: a long GRB detected with INTEGRAL
  15. GRB 140709A: Continued RATIR Optical and NIR Observations
  16. GRB 140710A: Swift-XRT refined Analysis
  17. GRB 140710A: Swift-BAT refined analysis
  18. GRB 140710A: Swift/UVOT Upper Limits
  19. GRB 140709B: update of Khureltogot optical upper limit
  20. GRB 140710A: Gemini-N redshift of likely host
  21. GRB 140710A: Enhanced Swift-XRT position
  22. GRB 140710A: RATIR Optical and NIR Observations
  23. GRB 140710A: P60 Confirmation of Afterglow
  24. GRB 140710A: correction to GCN #16565
  25. GRB 140710A: GROND Detection of NIR Afterglow Candidate
  26. GRB 140709A: 10.4m GTC optical decay
  27. GRB 140710A: Swift detection of a burst
  28. GRB 140709B: Swift-XRT refined Analysis
  29. GRB 140709B: Fermi GBM detection
  30. GRB 140709B: Swift-BAT refined analysis
  31. GRB 140709A : Virtual Telescope optical observations
  32. GRB 140709B: Khureltogot optical upper limit
  33. GRB 140709B: OSN optical limit
  34. GRB 140709B: Enhanced Swift-XRT position
  35. GRB 140709A: Fermi GBM detection
  36. GRB 140709A: BOOTES-2 and OSN optical observations
  37. GRB 140709A, Swift-BAT refined analysis
  38. GRB 140709B: MASTER optical observation
  39. GRB 140709B: Swift detection of a burst
  40. GRB 140709A: Swift-XRT refined Analysis
  41. GRB 140709A: Swift/UVOT Upper Limits
  42. GRB 140709A - UVOT-enhanced XRT position
  43. GRB 140709A: RATIR Optical and NIR Observations
  44. GRB 140709A: Swift detection of a burst
  45. Fermi GBM trigger 140708682 is not a GRB
  46. GRB 140705A: Nishi-Harima NIR upper limits
  47. GRB 140703A: AMI 15 GHz detection
  48. GRB 140705A / SGR 1935+2154: VLA 6 GHz observations
  49. GRB 140706A: Swift/UVOT Detection
  50. GRB 140703A: Swift/UVOT Upper Limits
  51. GRB 140706A: Swift-BAT refined analysis
  52. GRB 140706A: Swift-XRT refined Analysis
  53. GRB 140706A: Fermi GBM detection
  54. GRB 140703A: AAO optical observations
  55. Pre-discovery observations of SGR 1935+2154 in Swift archival data
  56. GRB140706A: GROND detection of the Optical/NIR afterglow
  57. GRB 140705A / SGR 1935+2154: Probable association with supernova remnant G57.2+0.8
  58. GRB 140706A: Enhanced Swift-XRT position
  59. GRB 140706A: Swift detection of a burst with an optical counterpart
  60. SGR 1935+2154: Swift-BAT observations of additional short soft events
  61. GRB 140705A / SGR 1935+2154: FTN observations
  62. GRB 140705A / SGR 1935+2154: Optical observations from 10.4m GTC
  63. GRB 140705A: KAIT Optical Upper Limit
  64. GRB 140705A: MITSuME Ishigakijima upper limits
  65. GRB 140705A: Swift-XRT refined Analysis
  66. GRB 140705A: MITSuME Okayama upper limits
  67. GRB 140705A: Swift/UVOT Upper Limits
  68. GRB 140705A: Swift-BAT refined analysis of a possible newly discovered SGR 1935+2154
  69. GRB 140705A: Enhanced Swift-XRT position
  70. GRB 140705A: Swift detection of a short burst
  71. GRB 140621A: Suzaku WAM observation of the prompt emission
  72. GRB 140629A: SAO RAS Rc band photometry
  73. GRB 140629A, Optical observations
  74. GRB 140703A: VLA K-band detection
  75. GRB 140703A: CARMA 3mm detection
  76. GRB 140703A: P60 observations of a red, slowly-fading afterglow
  77. GRB 140703A: RATIR Optical and NIR Observations
  78. GRB 140703A: Fermi GBM detection
  79. GRB 140703A: Monte Agliale Observatory optical observations
  80. GRB 140703A: Swift-XRT refined Analysis
  81. GRB 140703A: Swift-BAT refined analysis
  82. Correction to GCN 16507: GRB 140703A!
  83. GRB 140703A: MASTER optical observations
  84. GRB 140703A: Enhanced Swift-XRT position
  85. GRB140703A: 10.4m GTC redshift
  86. GRB 140703A: BOOTES-2 and OSN optical observations
  87. GRB 140703A: Swift detection of a burst
  88. GRB 140619C: Suzaku WAM observation of the prompt emission
  89. GRB 140629A: MITSuME Akeno Optical observation
  90. GRB 140629A: MASTER-Net preliminary light curve
  91. GRB 140629A: SAO RAS monitoring
  92. GRB 140629A: additional P60 observations
  93. Fermi 425667201: optical counterpart search
  94. GRB 140629A: Nishi-Harima NIR Observations
  95. Konus-Wind observation of GRB 140629A
  96. GRB 140629A: Swift/UVOT Detection
  97. GRB 140629A: TNG redshift confirmation
  98. GRB140629A: VATT optical observations
  99. GRB 140629A: P60 observations
  100. GRB 140629A: Swift-XRT refined Analysis

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