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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 140903A: Possible optical variability
  2. GRB 140903A: NOT optical and NIR observations
  3. GRB 140901B: Swift XRT observation
  4. GRB 140903A: FTN observations
  5. GRB 140818B: TShAO optical upper limit
  6. GRB 140903A: ISON-Kislovodsk observations
  7. GRB 140903A: MAXI/GSC upper limit
  8. GRB 140903A: 6 GHz VLA detection
  9. GRB 140903A: Pan STARRS images of the field
  10. GRB 140901B: Fermi GBM detection
  11. GRB 140903A: tentative spectroscopic redshift
  12. GRB 140901B found in ground analysis of BAT data
  13. GRB 140903A: Swift/UVOT Upper Limits
  14. GRB 140903A: Swift-BAT Spectral lag analysis
  15. GRB 140903A: P60 Optical Observations
  16. GRB140903A: Discovery Channel Telescope Optical Detection
  17. GRB 140903A: Swift-BAT refined analysis
  18. GRB 140903A: Swift-XRT refined Analysis
  19. GRB 140903A: Coincident galaxy cluster in archival images
  20. GRB 140903A: Confirmed Swift detection of a short burst
  21. GRB 140903A: Preliminary Swift/XRT localization
  22. GRB 140903A: Swift detection of a possible burst
  23. GRB 140901A: Fermi GBM detection
  24. IPN Triangulation of GRB 140901A (short/hard/very intense)
  25. GRB 140831A: iPTF observations of a possible short burst detected by Fermi GBM
  26. GRB 140829A: Fermi GBM Detection
  27. GRB 140829A: iPTF optical observations
  28. GRB140818B, the review of the sky area in plate archives
  29. GRB 140828A, Swift-BAT refined analysis
  30. Konus-Wind observation of GRB 140825A
  31. GRB 140828A: Fermi GBM observation
  32. Swift Mission Operations Center Fully Operational
  33. IPN Triangulation of GRB 140825A (very intense/long)
  34. GRB 140828A: Swift detection of a burst
  35. IPN Triangulation of GRB 140824B
  36. Swift Burst Response Reenabled
  37. GRB 140818B: TLS observations
  38. GRB 140824A: optical upper limit in CrAO
  39. GRB 140824B: Swift observations
  40. Fermi TRIGGER_NUM 430645968: MASTER OT inside error box
  41. Swift Mission Operations Center Moving Tomorrow
  42. GRB 140824B: Fermi GBM Detection
  43. GRB 140821A: Fermi GBM Detection
  44. Fermi TRIGGER_NUM 430583595: MASTER OT 20 hours later
  45. Fermi TRIGGER_NUM 430583595: MASTER OT JR011101.13+603337.5 detection
  46. GRB 140824A: NOT optical upper limits
  47. GRB 140824A: OSN optical limit
  48. GRB 140824A: Swift-XRT refined Analysis
  49. GRB 140824A: Swift-BAT refined analysis
  50. GRB 140824A: Enhanced Swift-XRT position
  51. GRB 140824A: MITSuME Ishigakijima upper limits
  52. GRB 140824A: Swift/UVOT Upper Limits
  53. GRB 140824A: Swift detection of a burst
  54. GRB 140817A: NOT optical observations
  55. Fermi GBM Trigger 140819576/ 430148973/ MASTER OT
  56. GRB 140817A: Khureltogot optical upper limit
  57. GRB 140818B: ISON-Kislovodsk and ISON-Burakan optical upper limit
  58. Fermi trigger 430148973: Swift-XRT observation
  59. GRB 140818A: GROND confirmation of afterglow candidate
  60. GRB 140808A/iPTF14eag: AMI 15 GHz detection
  61. GRB140819A: Deep GROND Upper Limits
  62. Fermi 430148973/MASTER candidate: LCO-Sutherland observations
  63. Fermi trigg_num 430148973: OSN I-band observations
  64. GRB 140818B, Swift-BAT refined analysis
  65. Fermi trigg_num 430148973: bright OT inside large error box!
  66. Konus-Wind observation of GRB 140818A
  67. GRB 140818B : Correction to GCN 16713
  68. GRB 140818B: Swift/UVOT Upper Limits
  69. GRB 140818B: Swift-XRT refined Analysis
  70. Radio upper limit on the GRB 140808A with the GMRT
  71. GRB 140818B: Fermi GBM detection
  72. GRB140818B : GROND afterglow candidate
  73. GRB 140818B: Enhanced Swift-XRT position
  74. GRB 140818B: OSN I-band afterglow candidate
  75. GRB 140817A: Swift/UVOT Afterglow Detection
  76. GRB 140818B: Swift detection of a burst
  77. GRB 140818A - Fermi GBM Detection
  78. Swift detection of SAX J1712.6-3739
  79. GRB 140818A: Swift-XRT and UVOT potential afterglow detection
  80. GRB 140818A: Correction to GCN 16702
  81. Konus-Wind observation of GRB 140817A
  82. GRB 140818A Tiled Swift observations
  83. GRB 140818A: MAXI/GSC detection
  84. GRB 140817A: Swift-XRT refined Analysis
  85. GRB 140817A: Fermi GBM Detection
  86. GRB 140817A: Swift-BAT refined analysis
  87. GRB 140817A draft circular on nearby galaxy
  88. GRB 140817A: Enhanced Swift-XRT position
  89. GRB 140817A: Swift-XRT position
  90. GRB 140817A: Swift detection of a burst
  91. GRB 140808A / PTFeag: VLA K-band observations
  92. GRB 140815A: GROND afterglow candidate
  93. Swift Trigger 609694 is probably not an astrophysical source
  94. GRB 140815A: Swift-XRT observations
  95. GRB 140815A: A long GRB detected by INTEGRAL
  96. GRB 140814A: Swift-XRT and UVOT observations
  97. GRB 140814A: MASTER optical follow-up inspection
  98. GRB 140814A: Swift-XRT and UVOT observations
  99. GRB 140814A: MAXI/GSC detection
  100. Swift Mission Operations Center Moving

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