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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"

42589 results found.

  1. GRB 130427A: KAIT optical observations
  2. GRB 130425A: Suzaku WAM observation of the prompt emission
  3. GRB 130427A: SARA-N optical observations
  4. GRB 130427A: VLA 20 GHz detection
  5. GRB 130427A: ABT optical observations
  6. GRB 130427A: High-energy neutrino search
  7. GRB 130427A: GMRT radio detection
  8. GRB 130427A: Continued GMG optical observations
  9. GRB 130427A: Nishi-Harima Optical Spectroscopic Observations
  10. GRB 130427A: photo-z of possible SDSS host galaxy
  11. GRB 130427A: high energy gamma-ray detection by AGILE
  12. GRB 130427A: Continued RATIR Optical and NIR Observations
  13. Swift-BAT trigger 554135 is noise
  14. GRB 130427A: Challis Observatory optical observations
  15. GRB 130427A: Continued Skynet/PROMPT Observations
  16. GRB 130427A: further GMG observations
  17. GRB 130427A: Fermi-LAT refined analysis
  18. GRB 130427A: SARA-N detection
  19. GRB 130427A: Continued RATIR Optical and NIR Observations
  20. GRB 130427A: CrAO RT-22 36 GHz observation
  21. GRB 130427A in the Ep,i - Eiso plane
  22. GRB 130427A: Improved Swift-XRT analysis
  23. GRB 130425: MASTER-Net optical observations
  24. GRB 100728A: GROND host detection and X-shooter redshift
  25. GRB 130427A: Skynet/PROMPT Observations
  26. GRB 130427B: RATIR Optical and NIR Observations
  27. GRB 130427A: Nishi-Harima NIR Observations
  28. GRB 130427A: CARMA 3mm observations
  29. GRB 130427B: Tentative VLT/X-shooter redshift
  30. GRB 130427A: VLT/X-shooter redshift confirmation
  31. GRB 130427A optical time series
  32. GRB 130427A: Continued iTelescope T21 optical observations
  33. Konus-Wind observation of GRB 130427A
  34. GRB 130427A: Kanata/HOWPol optical imaging polarimetry
  35. GRB 130427A: Swift-XRT refined Analysis
  36. GRB 130427A: SPI-ACS/INTEGRAL observations
  37. GRB 130427A: Continued RATIR Optical and NIR Observations
  38. GRB 130427A: CARMA 85 GHz detection
  39. GRB 130427A: SNUO/SOAO/BOAO Observation
  40. GRB 130427A: VLA 5 GHz detection
  41. GRB 130427B: Swift-XRT refined Analysis
  42. GRB 130427A: NOT optical photometry and redshift
  43. GRB 130427A: RAPTOR Bright Counterpart Before Swift Trigger
  44. GRB 130427A: T100 observations
  45. GRB 130427A: optical observations in CrAO
  46. GRB 130427A: Fermi GBM observation
  47. GRB130427A: Swift/UVOT followup observations of an Optical Afterglow
  48. GRB 130427A: Fermi-LAT detection of a burst
  49. GRB 130427A: Swift-BAT refined analysis
  50. GRB 130427B: Swift-BAT refined analysis
  51. GRB 130427A: Zadko observatory - Gingin optical observations
  52. GRB 130427B: Enhanced Swift-XRT position
  53. GRB 130427A: GMG optical observation
  54. GRB 130427A: Optical Observations
  55. GRB 130427A: MAXI/GSC detection
  56. GRB 130427B: Faulkes Telescope North afterglow detection
  57. GRB 130427B: Swift detection of a burst with optical counterpart
  58. GRB 130427A: RATIR Optical and NIR Observations
  59. GRB 130427A: Weihai optical observations
  60. GRB 130427A: iTelescope T11 optical observations
  61. GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
  62. GRB 130427A: Gemini-North redshift
  63. GRB 130427A: PAIRITEL NIR Detections
  64. GRB 130427A: Faulkes Telescope North detection
  65. GRB 130427A: P60 early detection
  66. GRB 130427A: early optical observations
  67. GRB 130427A: P60 early nondetection
  68. GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
  69. Konus-Wind observation of GRB 130425A
  70. IPN Triangulation of GRB 130425A
  71. GRB 130420A: Continued Skynet/GORT Observations/Detections
  72. GRB 130420B: CARMA and VLA radio observations
  73. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  74. GRB 130425A: Fermi GBM detection
  75. GRB 130420A: Continued RATIR Optical and NIR Observations
  76. GRB 130420A: ROTSE-III data analysis
  77. GRB 130420A: Continued RATIR Optical and NIR Observations
  78. GRB 130418A: Continued RATIR Optical and NIR Observations
  79. GRB 130420A: Redshift from 10.4m GTC
  80. GRB 130420A: Early RAPTOR Simultaneous Multi-Color Observations
  81. GRB 130420B: Fermi GBM observation
  82. GRB 130418A: WSRT radio observation
  83. Swift Trigger 554135 is probably not a GRB or transient
  84. GRB 130420B: RATIR Optical and NIR Observations
  85. GRB 130420A: Continued RATIR Optical and NIR Observations
  86. GRB 130420B: Swift-XRT refined Analysis
  87. GRB 130420A: Fermi GBM observation
  88. GRB 130420A: ISON-NM optical observations
  89. Skynet/GORT observations of GRB130420A
  90. GRB 130420B: Weihai optical upper limit
  91. GRB 130420A: Swift/UVOT Detection
  92. GRB130420B: GMG optical upper limit
  93. GRB 130420A: Swift-XRT refined Analysis
  94. GRB 130420B: Enhanced Swift-XRT position
  95. GRB 130420B, Swift-BAT refined analysis
  96. GRB 130420A, Swift-BAT refined analysis
  97. GRB 130420A: GMG optical observation
  98. Konus-Wind observation of GRB 130418A
  99. GRB 130420A: Enhanced Swift-XRT position
  100. GRB130420A : Xinglong TNT optical upper limit

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