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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"

23601 results found.

  1. GRB 090516C: Fermi GBM detection
  2. GRB 090520 Swift-BAT detection of a burst in ground analysis
  3. GRB 090516B: Fermi GBM detection
  4. GRB 090519: Swift-XRT refined analysis
  5. GRB 090519: GROND observation
  6. GRB 090519: Swift/UVOT Upper Limits
  7. GRB 090519, Swift-BAT refined analysis
  8. GRB 090519: TAROT Calern observatory optical observations
  9. GRB 090519: Swift detection of a burst
  10. GRB 090511: Fermi GBM Detection
  11. GRB 090514: Fermi GBM detection
  12. GRB 090518, Swift-BAT refined analysis
  13. GRB 090516, RIMOTS optical upper limits
  14. GRB090513: Fermi GBM detection
  15. GRB 090518: Swift detection of a burst
  16. GRB 090516: Swift-BAT refined analysis
  17. GRB 090516 - Zadko Telescope observations
  18. GRB 090516: Swift/UVOT Observations
  19. GRB 090516: Faulkes Telescope South optical afterglow
  20. GRB 090516: Swift detection of a burst
  21. GRB 090515: Lick Upper Limits
  22. GRB 090515: MMT/MMIRS NIR Upper Limit
  23. GRB 090515: Swift/UVOT Observations
  24. GRB 090515: Swift-BAT refined analysis
  25. GRB 090509 - Zadko Telescope observations
  26. GRB 090515: Gemini-N upper limit
  27. GRB 090515: Super-LOTIS Upper Limits
  28. GRB 090515: PAIRITEL Upper Limits
  29. GRB 090515: Swift detection of a short burst
  30. GRB 090510: Suzaku WAM observation of the prompt emission
  31. GRB 090510: GROND observations
  32. GRB 090510: Swift/UVOT host galaxy candidates
  33. GRB 090509, further Swift-BAT refined analysis
  34. Konus-Wind observation of GRB 090510
  35. AGILE detection of GRB 090510
  36. GRB 090510: UVOT refined analysis
  37. GRB 090510: NOT afterglow confirmation
  38. GRB 090510: Swift-BAT refined analysis
  39. GRB 090510: Fermi GBM detection
  40. GRB 090509: Swift-BAT refined analysis
  41. GRB 090510: Swift detection of a short hard burst
  42. GRB 090509: GROND afterglow candidate
  43. GRB 090509: Swift detection of a burst
  44. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  45. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  46. GRB 090428B: Suzaku WAM observation of the prompt emission
  47. GRB 090429D: Fermi GBM detection
  48. GRB 090429C: Fermi GBM detection
  49. GRB 090429B: Swift/UVOT Upper Limits
  50. GRB 090429A: Swift/UVOT Upper Limits
  51. GRB 090424: YNAO-GMG observations
  52. GRB 090429A: Swift-XRT refined analysis
  53. GRB 090427C: Fermi GBM detection
  54. GRB 090427B: Fermi GBM detection
  55. GRB 090426C: Fermi GBM detection
  56. GRB 090426B: Fermi GBM detection/observation
  57. Konus-Wind observation of very bright GRB 090427
  58. GRB 090429B: RIMOTS optical upper limits
  59. GRB 090429B: Swift-BAT refined analysis
  60. GRB 090429A: Swift-BAT refined analysis
  61. GRB 090426: YNAO-GMG observations
  62. GRB 090429B: GROND Observations
  63. GRB 090429B: Swift detection of a burst
  64. GRB 090429: Swift detection of a burst
  65. GRB 090424 : Multiband Optical observation from Nainital
  66. IPN triangulation of very bright GRB 090427
  67. GRB 090426: R-band limit
  68. GRB 090424: Continued R-band monitoring
  69. GRB 090423: millimeter detection
  70. GRB 090426: Swift/BAT spectral lag results
  71. GRB 090424: Suzaku WAM observation of the prompt emission
  72. GRB 090426: VLT spectroscopy
  73. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  74. GRB 090426: Near infrared observation with ISLE at OAO
  75. GRB 090426: Okayama MITSuME optical observation
  76. GRB 090426 Keck LRIS redshift
  77. GRB 090426: Swift-BAT refined analysis
  78. GRB 090423: GROND second epoch imaging and refined SED
  79. GRB 090426: Swift detection of a burst with an optical counterpart
  80. GRB090424: R-band detection (37.5 hrs post-burst), jet break?
  81. GRB 090424: MASTER-Net prompt optical limit
  82. GRB090424: BVRI/R-band detection after 15 hrs burst
  83. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  84. GRB090423: Y-band limit
  85. GRB 090423: Y-band field calibration update/correction
  86. GRB 090423: Swift/BAT spectral lag results
  87. GRB 090424: Liverpool Telescope observations
  88. GRB 090424: Optical observations from 1.23m CAHA
  89. GRB 090423: energetic, luminosity and jet break
  90. GRB 090424: MASTER-Net prompt optical observations
  91. GRB 090424: Swift-BAT refined analysis
  92. GRB 090424: Fermi GBM Observation
  93. GRB 090422: Fermi GBM observation
  94. GRB 090424: ROTSE-III Confimation of Optical Counterpart
  95. GRB 090424: Swift detection of a burst with an optical counterpart
  96. GRB 090423: Refined TNG analysis
  97. GRB090423: Y-band field calibration
  98. GRB 090423: Near infrared observation at Okayama Observatory
  99. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  100. GRB 090423: TNG Amici spectrum

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