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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"

26922 results found.

  1. GRB 120311B: Swift-XRT observations
  2. GRB 120311A, Swift-BAT refined analysis
  3. GRB 120311B: Swift detection of a burst
  4. GRB 120311A: Swift/UVOT Upper Limits
  5. GRB 120311A: CAHA 1.23m I-band early observations
  6. GRB 120311A: Swift-XRT observations
  7. GRB 120311A: Liverpool Telescope optical candidate
  8. GRB 120311A: Swift detection of a burst
  9. GRB 120308A: Swift/UVOT Detection
  10. GRB 120308A: Swift-XRT refined Analysis
  11. GRB 120308A: Swift-BAT refined analysis
  12. GRB 120308A: PAIRITEL NIR observations
  13. GRB 120308A: confirmation of the optical afterglow
  14. GRB 120308A: Liverpool Telescope optical afterglow candidate
  15. GRB 120308A: Swift detection of a burst
  16. GRB 120305A: D50 optical limits
  17. GRB 120302A: Fermi GBM Observation
  18. GRB 120305A: Swift/UVOT Upper Limits
  19. GRB 120305A: Swift-XRT refined Analysis
  20. GRB 120305A: Swift-BAT refined analysis
  21. GRB 120305A - Liverpool Telescope Observations
  22. GRB 120305A: Swift detection of a short burst
  23. GRB 120302A: GROND detection of an afterglow candidate
  24. GRB 120302A, Swift-BAT refined analysis
  25. GRB 120229A, Swift-BAT refined analysis
  26. GRB 120229A: Swift detection of a short burst
  27. Konus-Wind observation of GRB 120226A
  28. GRB 120226A: Fermi-GBM and Fermi-LAT detections; LAT position retraction
  29. GRB 120226A: Fermi-LAT data analysis
  30. IPN Triangulation of GRB 120226A
  31. GRB 120227A: RAPTOR Limit During the Gamma-Ray Emitting Interval
  32. GRB 120224A: optical observation in Mondy observatory
  33. GRB 120226A: Fermi-LAT detection of a burst
  34. GRB 120224A: GROND detection of the afterglow candidate
  35. GRB 120224A: Swift-XRT refined Analysis
  36. Swift Trigger 516027 is CC Eri
  37. GRB 120224A: Swift/UVOT Upper Limits
  38. GRB 120224A: Swift-BAT refined analysis
  39. GRB 120224A: FTN optical observations
  40. GRB 120224A: Swift detection of a burst
  41. GRB 120219A: MASTER prompt and early optical limit and OT discussion
  42. GRB 120219A, optical observations
  43. GRB 120215A: MITSuME Akeno Optical upper limits
  44. GRB 120219A: Swift-XRT refined Analysis
  45. GRB 120219A: Swift/UVOT Upper Limits
  46. GRB 120219A: Swift-BAT refined analysis
  47. GRB 120219A: MASTER-NET prompt and early optical observations
  48. GRB 120219A: Swift detection of a burst
  49. GRB 120218A: Swift-BAT refined analysis
  50. GRB 120218A: Swift detection of a burst
  51. GRB 120215A: Swift/UVOT Upper Limits
  52. GRB 120215A: Swift-XRT refined Analysis
  53. Fermi GBM detection of an SGR-like burst
  54. GRB 120215A: Swift-BAT refined analysis
  55. GRB 120215A: Swift detection of a burst
  56. GRB 120213A: Swift-XRT refined Analysis
  57. GRB 120213A: Swift/UVOT Upper Limits
  58. GRB 120212A: Fermi GBM observation
  59. GRB 120213A: Swift-BAT refined analysis
  60. GRB 120212A: Swift-XRT refined Analysis
  61. GRB 120213A: Swift detection of a burst
  62. GRB 120212A: NOT optical observation
  63. GRB 120212A: Swift/UVOT Detection
  64. GRB 120212A: Swift-BAT refined analysis
  65. GRB 120211A: MITSuME Okayama Ks-band Observation
  66. GRB 120212A: Kanata/HOWPol optical observation
  67. GRB 120212A: Swift-XRT observations
  68. GRB 120212A: Swift/UVOT detection
  69. GRB 120211A: GROND Upper limits
  70. GRB 120212A: Swift detection of a burst
  71. GRB 120211A, optical observations
  72. GRB 120211A: Swift-XRT refined Analysis
  73. GRB 120211A: Swift/UVOT Upper Limits
  74. GRB 120211A: MASTER early optical observations
  75. GRB 120211A: Swift-BAT refined analysis
  76. GRB 120211A: MITSuME Okayama Ks-band upper limit
  77. GRB 120211A - Faulkes Telescope South Observations
  78. GRB 120211A: Swift detection of a burst
  79. LS I +61 303: Swift-BAT refined analysis
  80. GRB 120202A: D50 optical limits
  81. Swift detection of a burst from LS I +61 303
  82. GRB 120202A: GROND observations
  83. GRB 120202A: Swift/XRT and UVOT observations
  84. GRB 120202A: TAROT Calern observatory optical observations
  85. GRB 111228A: Possible host detected by Swift/UVOT
  86. GRB 120127A / P48 Imaging
  87. GRB 120116A: optical upper limit
  88. GRB 120119A : SMA submm follow-up observation
  89. Fermi GBM trigger 120123.169 is not a GRB
  90. GRB 120119A: GRT detection of early afterglow
  91. GRB 111225A: optical observations
  92. GRB 120121A: Swift/UVOT Upper Limits
  93. GRB 120121A: Swift-XRT refined Analysis
  94. GRB 120121A: Swift-BAT refined analysis
  95. GRB 120121A: Swift detection of a burst
  96. GRB 120119A, Swift-BAT refined analysis
  97. GRB 120119A: TAROT La Silla observatory optical observations
  98. GRB 120119A: Swift/UVOT Observations
  99. GRB 120119A: Swift-XRT refined Analysis
  100. GRB 120119A: Fermi GBM observation

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Download all Circulars as a .tar.gz archive (updated once a day):
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