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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 140521A: Fermi GBM Detection
  2. GRB 140423A: TShAO optical observations
  3. GRB 140521A: AAO optical observations
  4. GRB 140521A: Swift-BAT refined analysis
  5. GRB 140521A: AROMA-N Optical Observation
  6. GRB 140521A: MITSuME Okayama upper limits
  7. GRB 140516A: further Swift-XRT analysis
  8. GRB 140521A: MASTER optical observations
  9. GRB 140521A: Swift detection of a burst
  10. GRB 140512A: Redshift from NOT
  11. GRB 140518A: T100 observations
  12. GRB 140518A: Continued RATIR Optical and NIR Observations
  13. GRB 140512A: MASTER prompt and afterglow optical observations
  14. GRB 140518A, Swift-BAT refined analysis
  15. GRB 140518A: Swift-XRT refined Analysis
  16. GRB 140518A: Skynet GORT Detections of the Optical Afterglow
  17. GRB 140518A: Swift/UVOT Upper Limits
  18. GRB 140518A: RATIR Optical and NIR Observations
  19. GRB 140518A: Gemini-N redshift
  20. GRB 140518A: P60 i-/z-band detections
  21. GRB 140518A: KAIT optical candidate
  22. GRB 140518A: Swift detection of a burst
  23. GRB 140516A: RATIR Optical and NIR Observations
  24. GRB 140516A: Subaru NIR imaging observations
  25. GRB 140516A: 6 GHz upper limit
  26. GRB 140516A: Gemini-North limit on an optical afterglow
  27. GRB 140516A: Swift/UVOT Upper Limits
  28. GRB 140516A: Swift-BAT refined analysis
  29. GRB 140516A: Swift-XRT refined Analysis
  30. GRB 140516A: NOT optical observations
  31. GRB 140516A: Enhanced Swift-XRT position
  32. GRB 140516A: MASTER early optical observations
  33. GRB 140516A: ISON-Kislovodsk optical observations
  34. GRB 140516A: TNG optical observations
  35. GRB 140516A: Swift detection of a short burst
  36. GRB 140515A: Swift-BAT refined analysis
  37. GRB 140515A: VLA Detection
  38. GRB 140515A : TNG near-infrared observations
  39. GRB 140419A: Continued Mondy optical observations
  40. GRB 140515A: GROND observation of the afterglow
  41. GRB 140515A: Spectroscopy from the 10.4m GTC
  42. GRB 140515A: Optical observations from the 2.5 m NOT
  43. GRB 140515A: Swift-XRT refined Analysis
  44. GRB 140515B: MAXI/GSC detection
  45. GRB 140515A: KAIT Optical Upper Limit
  46. GRB 140515A: Gemini-North imaging
  47. GRB 140515A: Swift/UVOT Upper Limits
  48. GRB 140423A: HCT optical observations
  49. GRB 140515A: MITSuME Akeno upper limits
  50. GRB 140515A: Enhanced Swift-XRT position
  51. GRB 140515A: Gemini-N redshift
  52. Trigger 599041: Swift detection of SFXT IGR J16479-4514
  53. GRB 140515A: Swift detection of a burst
  54. GRB 140508A: VLA detection
  55. Konus-Wind observation of GRB 140512A
  56. GRB 140423A: AAO optical upper limits
  57. GRB 140512A: Continued UVOT Observations
  58. GRB 140512A: Fermi GBM detection
  59. GRB 140512A: Xinglong TNT optical observation
  60. GRB 140508A: Mondy upper limit
  61. GRB 140508A: MITSuME Akeno Optical observation
  62. GRB 140512A: Swift-BAT refined analysis
  63. GRB140512A : GROND observations
  64. GRB 140512A: Swift-XRT refined Analysis
  65. GRB 140512A: Enhanced Swift-XRT position
  66. Swift Observations of GRB 140508A
  67. GRB 140512A: Optical observations from the 2.5 m NOT
  68. GRB 140428A: GROND afterglow confirmation
  69. GRB 140512A: Mondy optical detection
  70. GRB 140512A: MASTER OT decay and early light curve
  71. GRB 140512A: Swift detection of a burst with an optical counterpart
  72. GRB 140512A: MASTER optical observations
  73. GRB 140423A: Mondy optical observations
  74. GRB 140508A: Continued RATIR Optical and NIR Observations
  75. Fermi GBM Trigger 140429551 - Detection of a burst from SGR 1806-20
  76. GRB 140508A: ​HCT spectroscopy
  77. GRB 140508A: Swift/UVOT Detection
  78. GRB 140509B: MAXI/GSC detection
  79. GRB 140509A: Swift/UVOT Detection and photo-z
  80. GRB 140509A: Swift-BAT refined analysis
  81. VHE gamma-ray observations by MAGIC of SWIFT Trigger 596958
  82. GRB 140509A: Swift-XRT refined Analysis
  83. GRB 140508A: RATIR Optical and NIR Observations
  84. GRB 140508A: Optical Observations via Virtual Telescope
  85. Konus-Wind observation of GRB 140508A
  86. GRB 140509A: Enhanced Swift-XRT position
  87. GRB 140508A: Swift-XRT observations
  88. GRB 140508A: WHT spectroscopy
  89. GRB 140509A: Swift detection of a burst with an optical counterpart
  90. GRB 140508A: NOT photometry and spectroscopy
  91. GRB 140508A: SAO RAS and MASTER photometric and spectroscopic observations
  92. GRB 140508A: 1.23m CAHA BVRI-band observations
  93. GRB 140508A: iPTF optical transient candidate
  94. IPN triangulation of GRB 140508A
  95. GRB 140508A: Fermi GBM detection
  96. Konus-Wind observation of GRB 140506A
  97. GRB 140430A: MITSuME Akeno upper limits
  98. GRB 140502A: ISON-NM early optical limit
  99. GRB 140506A: Fermi GBM Detection
  100. GRB 140506A: Swift/UVOT Detection

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