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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 120320A: Gemini-N and UKIRT observations
  2. Fermi GBM trigger 120319.237 is not a GRB
  3. GRB 120320A: Enhanced Swift-XRT position
  4. Konus-Wind observation of GRB 120316A
  5. IPN Triangulation of GRB 120316A
  6. GRB 120320A: MASTER optical observations
  7. GRB 120320A: Swift detection of a burst
  8. GBM trigger 353549464 (GRB 120316A?) : High-energy photon emission in Fermi/LAT data
  9. GRB 111228A: possible detection of the SN with the TNG
  10. Trigger 517876 is a Swift detection of GX 5-1
  11. GRB 120302A: Swift XRT refined analysis
  12. GRB 120312A, the review of the sky area in plate archives
  13. GRB 120312A: CrAO optical upper limit
  14. GRB 120312A: Gemini and UKIRT imaging
  15. GRB 120311A, the review of the sky area in plate archives
  16. Fermi GBM triggers 120309.265 and 120309.402 are not GRBs
  17. Fermi GBM triggers 120305.186, 120305.802 and 120306.823 are not GRBs
  18. GRB 120311A: Optical follow-up
  19. GRB 120311B: Optical follow-up
  20. GRB 120311A: C88 optical limits
  21. GRB 120312A: Swift/UVOT Upper Limits
  22. GRB 120312A: MASTER-NET optical observations
  23. GRB 120312A: WHT candidate afterglow
  24. GRB 120312A: NOT observations
  25. GRB 120312A: Swift-XRT refined Analysis
  26. GRB 120312A: Swift-BAT refined analysis
  27. GRB 120311A: VLT/X-shooter observations
  28. GRB 120311B: C88 optical limits
  29. GRB 120312A: Swift detection of a burst
  30. GROND observations of GRB 120311A
  31. GRB 120311B: Swift/UVOT Upper Limits
  32. GRB 120311B: MITSuME Okayama Optical upper limits
  33. GRB 120311B: Faulkes Telescope North observations
  34. GRB 120311B: Swift-XRT refined Analysis
  35. GRB 120311A: Swift-XRT refined Analysis
  36. GRB 120311B: Enhanced Swift-XRT position
  37. GRB 120311B: Swift-BAT refined analysis
  38. GRB 120311B: Swift-XRT observations
  39. GRB 120311A, Swift-BAT refined analysis
  40. GRB 120311B: Swift detection of a burst
  41. GRB 120311A: Swift/UVOT Upper Limits
  42. GRB 120311A: CAHA 1.23m I-band early observations
  43. GRB 120311A: Enhanced Swift-XRT position
  44. GRB 120311A: Swift-XRT observations
  45. GRB 120311A: Liverpool Telescope optical candidate
  46. GRB 120311A: Swift detection of a burst
  47. GRB 120308A : LOAO optical observation
  48. GRB 120308A: RTT150 optical observations
  49. GRB 120302A: RTT150 optical observations
  50. GRB 120308A: 1.23m CAHA I-band observations
  51. GRB 120308A: Further PAIRITEL NIR Observations
  52. GRB120308A: MITSuME Ishigakijima Optical Upper Limits
  53. GRB 120308A: Swift/UVOT Detection
  54. GRB 120308A: Swift-XRT refined Analysis
  55. GRB 120308A: Enhanced Swift-XRT position
  56. GRB 120308A: Swift-BAT refined analysis
  57. GRB 120308A: IAC80 I-band observations
  58. GRB 120308A: PAIRITEL NIR observations
  59. GRB 120308A: confirmation of the optical afterglow
  60. GRB 120308A: Liverpool Telescope optical afterglow candidate
  61. GRB 120308A: Swift detection of a burst
  62. GRB 120305A: D50 optical limits
  63. GRB 120305A: Swift spectral lag analysis
  64. GRB 120302A, the review of the sky area in plate archives
  65. GRB 120302A: Fermi GBM Observation
  66. GRB 120302A: Swift-BAT refined position and a possible XRT and UVOT counterpart
  67. GRB 120305A: Swift/UVOT Upper Limits
  68. GRB 120305A: EVLA deep limit on a radio counterpart
  69. GRB 120305A: Swift-XRT refined Analysis
  70. GRB 120305A: Enhanced Swift-XRT position
  71. GRB 120305A: Swift-BAT refined analysis
  72. GRB 120305A - Liverpool Telescope Observations
  73. GRB 120305A: MASTER-NET early optical observations
  74. GRB 120305A: Swift detection of a short burst
  75. GRB 120302A: GROND detection of an afterglow candidate
  76. GRB 120302A, Swift-BAT refined analysis
  77. GRB 111222A: Swift observation on 2012 February 06/07
  78. GRB 120302A found in ground analysis of BAT data
  79. GRB 120229A: Spectral lag analysis
  80. GRB 120229A, Swift-BAT refined analysis
  81. GRB 120229A: Swift detection of a short burst
  82. Konus-Wind observation of GRB 120226A
  83. GRB 120226A: Fermi-GBM and Fermi-LAT detections; LAT position retraction
  84. GRB 120226A: Fermi-LAT data analysis
  85. IPN Triangulation of GRB 120226A
  86. GRB 120227A: RAPTOR Limit During the Gamma-Ray Emitting Interval
  87. GRB 120224A: VLT/X-shooter observations
  88. GRB 120224A: optical observation in Mondy observatory
  89. GRB 120226A: Fermi-LAT detection of a burst
  90. GRB 120224A: GROND detection of the afterglow candidate
  91. GRB 120219A, the review of the sky area in plate archives
  92. GRB 120224A: Swift-XRT refined Analysis
  93. Swift Trigger 516027 is CC Eri
  94. GRB 120224A: Swift/UVOT Upper Limits
  95. GRB 120224A: Swift-BAT refined analysis
  96. GRB 120224A: FTN optical observations
  97. GRB 120224A: Enhanced Swift-XRT position
  98. GRB 120224A: Swift detection of a burst
  99. GRB_120215, the_review_of_the_sky_area_in_plate_archives
  100. GRB 1202019A: optical observation in Mondy observatory

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