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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"

5827 results found.

  1. GRB 090509: Fermi GBM observation
  2. GRB 090509 - Zadko Telescope observations
  3. GRB 090515: KAIT optical upper limits
  4. GRB 090515: Swift detection of a short burst
  5. GRB 090509, SMARTS optical/IR afterglow observations
  6. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  7. GRB 090429B: Swift detection of a burst
  8. GRB 090429: Swift detection of a burst
  9. GRB 090425: Fermi GBM detection
  10. GRB 090424: Swift detection of a burst with an optical counterpart
  11. GRB 090423 limiting magnitudes
  12. GRB 090423: Swift-BAT refined analysis
  13. GRB 090423: UKIRT K-band observations
  14. GRB 090423: Swift detection of a burst
  15. GRB 090418: ROTSE-III Confirmation of Optical Counterpart
  16. GRB 090418: Swift detection of a burst with optical afterglow
  17. GRB 090417B: Swift detection of a burst
  18. GRB 090409: Fermi GBM detection
  19. GRB 090331: Fermi GBM detection
  20. Konus-Wind observation of GRB 090328
  21. Fermi LAT and GBM detections of GRB090328
  22. GRB 090327: Fermi GBM detection
  23. GRB 090323: Swift-XRT refined analysis
  24. GRB 090324: SuperAGILE Localization of a Long GRB
  25. GRB 090313 - PAIRITEL NIR detections
  26. GRB 090313, GROND observations
  27. GRB 090313: Swift detection of a burst
  28. GRB 090313: Swift detection of a burst
  29. GRB 090205: Zadko Telescope late-time observations
  30. GRB 090306C: Fermi GBM detection
  31. Swift-BAT trigger 345396 is not a GRB
  32. IPN localization of short GRB 090305C
  33. GRB 090305: Magellan confirmation of the optical afterglow
  34. GRB090217: XRT analysis
  35. SGR activity seen by BAT during ICSP Ionospheric Events
  36. GRB 090205: Swift-XRT refined analysis
  37. GRB 090131: Suzaku WAM observation of the prompt emission
  38. GRB 090131: Fermi GBM detection
  39. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  40. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  41. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  42. GRB 090111: Swift detection of a burst
  43. Fermi/GBM detection of GRB 081225
  44. GRB 081222: MITSuME optical observation
  45. GRB081221: Fermi GBM observation
  46. GRB 081222: Swift detection of a burst with a bright optical afterglow
  47. GRB 081215A: Fermi GBM detection
  48. GRB 081213: Fermi GBM detection
  49. Fermi Gamma-ray Burst Monitor trigger 250533995 is not a GRB
  50. GRB 081210: Swift detection of a burst with optical afterglow
  51. GRB081203A: Optical observations at Ishigaki
  52. GRB 081109: Fermi GBM detection
  53. GRB 081109: REM NIR afterglow detection
  54. GRB 081109: Swift detection of a burst
  55. Radio observation of GRB 080520 with ATCA
  56. GRB 081104: Swift detection of a burst
  57. Radio observation of GRB 080130 with ATCA
  58. GRB 081102: Swift detection of a burst
  59. Radio observation of GRB 080229b with ATCA
  60. GRB 081029: UVOT Detection of the Optical Afterglow
  61. GRB 081029: Enhanced Swift-XRT position
  62. Radio observation of GRB 080303 with ATCA
  63. Radio observation of GRB 080411 with ATCA
  64. GRB 081029: ROTSE-III Detection of Optical Counterpart
  65. GRB 081029: Swift detection of a burst
  66. GRB 081021: Fermi GBM detection
  67. GRB 081028: Swift detection of a burst
  68. GRB 081012: Swift/XRT detection
  69. GRB 081008: VLT redshift confirmation
  70. GRB 081008: VLT/FORS2 spectroscopy
  71. GRB 081008: Swift detection of a burst with optical afterglow
  72. GRB 081007: Swift detection of a burst with optical afterglow
  73. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  74. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  75. Trigger 330353: Swift detection of a Galactic short soft burst
  76. GRB 080928: GROND DETECTION
  77. GRB 080928: Swift detection of a burst with an optical counterpart
  78. Swift trigger 325707: Swift-XRT upper limit
  79. GRB080916A: Suzaku WAM observation of the prompt emission
  80. GRB080922: Swift-XRT upper limit
  81. GRB 080915A: GROND upper limits
  82. GRB 080916A: GROND lightcurve
  83. GRB 080916A: Fermi GBM detection
  84. GRB 080916C: Swift XRT refined analysis
  85. Konus-Wind observation of GRB 080916A
  86. GRB 080915a, SMARTS optical/IR observations
  87. GRB 080916: Swift detection of a burst with optical afterglow
  88. GRB 080913: Swift-XRT refined analysis
  89. GRB 080906: Swift detection of a burst with optical afterglow
  90. GRB 080905B: Swift detection of a burst with possible optical counterpart
  91. GRB 080903: Astrotel-Caucasus optical observations
  92. GRB 080903: TAROT Calern observatory optical observations
  93. GRB 080903: Swift detection of a burst
  94. Swift-BAT trigger 322590 is not a GRB
  95. Swift trigger 322590: BAT detection of a possible burst
  96. SGR 0501+4516: XMM-Newton monitoring schedule
  97. SGR 0501+4516: Decline in Activity
  98. SGR 0501+4516: MDM Optical Observations
  99. Discovery of the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
  100. GRB 080810: Liverpool and Faulkes North observations

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