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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"

45411 results found.

  1. GRB 130427A: Kanata/HOWPol optical imaging polarimetry
  2. GRB 130427A: Swift-XRT refined Analysis
  3. GRB 130427A: SPI-ACS/INTEGRAL observations
  4. GRB 130427A: Continued RATIR Optical and NIR Observations
  5. GRB 130427A: CARMA 85 GHz detection
  6. GRB 130427A: SNUO/SOAO/BOAO Observation
  7. GRB 130427A: VLA 5 GHz detection
  8. GRB 130427B: Swift-XRT refined Analysis
  9. GRB 130427A: NOT optical photometry and redshift
  10. GRB 130427B: MITSuME Okayama upper limits
  11. GRB 130427A: RAPTOR Bright Counterpart Before Swift Trigger
  12. GRB 130427A: T100 observations
  13. GRB 130427A: optical observations in CrAO
  14. GRB 130427A: Fermi GBM observation
  15. GRB130427A: Swift/UVOT followup observations of an Optical Afterglow
  16. GRB 130427A: Fermi-LAT detection of a burst
  17. GRB 130427A: Swift-BAT refined analysis
  18. GRB 130427B: Swift-BAT refined analysis
  19. GRB 130427A: Zadko observatory - Gingin optical observations
  20. GRB 130427B: Enhanced Swift-XRT position
  21. GRB 130427A: GMG optical observation
  22. GRB 130427A: MITSuME Okayama Optical Observation
  23. GRB 130427A: Optical Observations
  24. GRB 130427A: MAXI/GSC detection
  25. GRB 130427B: Faulkes Telescope North afterglow detection
  26. GRB 130427B: Swift detection of a burst with optical counterpart
  27. GRB 130427A: RATIR Optical and NIR Observations
  28. GRB 130427A: Weihai optical observations
  29. GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
  30. GRB 130427A: Gemini-North redshift
  31. GRB 130427A: MITSuME Akeno Optical observation(T0+8000s~)
  32. GRB 130427A: PAIRITEL NIR Detections
  33. GRB 130427A: Faulkes Telescope North detection
  34. GRB 130427A: P60 early detection
  35. GRB 130427A: early optical observations
  36. GRB 130427A: P60 early nondetection
  37. GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
  38. Konus-Wind observation of GRB 130425A
  39. IPN Triangulation of GRB 130425A
  40. GRB 130420A: Continued Skynet/GORT Observations/Detections
  41. GRB 130420B: CARMA and VLA radio observations
  42. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  43. GRB 130425A: Fermi GBM detection
  44. GRB 130420A: Continued RATIR Optical and NIR Observations
  45. GRB 130420A: ROTSE-III data analysis
  46. GRB 130420A: Continued RATIR Optical and NIR Observations
  47. GRB 130418A: Continued RATIR Optical and NIR Observations
  48. GRB 130420A: Redshift from 10.4m GTC
  49. GRB 130420A: Early RAPTOR Simultaneous Multi-Color Observations
  50. GRB 130420B: Fermi GBM observation
  51. GRB 130418A: WSRT radio observation
  52. Swift Trigger 554135 is probably not a GRB or transient
  53. GRB 130420B: RATIR Optical and NIR Observations
  54. GRB 130420A: Continued RATIR Optical and NIR Observations
  55. GRB 130420B: Swift-XRT refined Analysis
  56. GRB 130420A: Fermi GBM observation
  57. GRB 130420A: ISON-NM optical observations
  58. Skynet/GORT observations of GRB130420A
  59. GRB 130420B: Weihai optical upper limit
  60. GRB 130420B: Swift/UVOT Upper Limits
  61. GRB 130420A: Swift/UVOT Detection
  62. GRB130420B: GMG optical upper limit
  63. GRB 130420A: Swift-XRT refined Analysis
  64. GRB 130420B: Enhanced Swift-XRT position
  65. GRB 130420B, Swift-BAT refined analysis
  66. GRB 130420A, Swift-BAT refined analysis
  67. GRB 130420A: GMG optical observation
  68. Konus-Wind observation of GRB 130418A
  69. GRB 130420A: Enhanced Swift-XRT position
  70. GRB130420A : Xinglong TNT optical upper limit
  71. GRB 130420B: Faulkes Telescope North observations
  72. GRB 130420A: Weihai Optical Observations
  73. GRB 130420B: MASTER-Net optical observations
  74. GRB 130420B: Swift detection of a burst
  75. GRB 130420A: RATIR Optical and NIR Observations
  76. GRB 130420A: PAIRITEL NIR detections
  77. GRB 130420A: ROTSE-III Detection of Optical Counterpart
  78. GRB 130420A: Swift detection of a burst with an optical counterpart
  79. GRB 130420A: Faulkes Telescope North candidate
  80. GRB 130418A: Continued RATIR Optical and NIR Observations
  81. GRB 130418A: Swift-XRT refined Analysis
  82. Swift Trigger 553930 is not an astrophysical source
  83. GRB 130418A: SMARTS optical/IR afterglow observations
  84. GRB 130418A: Submm observations from SMA
  85. GRB 130419A, Swift-BAT refined analysis
  86. GRB 130327B: Swift/XRT source is not the afterglow
  87. GRB 130419B (Swift trigger Trigger 553930): MASTER-Net optical observations
  88. Trigger 553930: Swift detection of a possible flare from HR 5110
  89. GRB 130418A: LOAO Observation
  90. GRB 130418A, Swift-BAT refined analysis
  91. GRB 130419A: Swift detection of a burst
  92. GRB130418A: VLT/X-shooter redshift confirmation
  93. GRB 130418A: REM NIR observations
  94. GRB 130418A: RATIR Optical and NIR Observations
  95. GRB 130418A: CARMA 3mm detection
  96. GRB 130418A: GROND detection of the optical-NIR afterglow
  97. GRB130418A: OSN 1.5m fading afterglow detection
  98. GRB 130418A: Swift/UVOT Detection and request for continuing coverage
  99. GRB 130418A: Enhanced Swift-XRT position
  100. GRB 130418A: TAROT Calern and TAROT la Silla observatory optical observations

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