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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"

32532 results found.

  1. Swift/UVOT observations of GRB100522A.
  2. GRB 100522A: Fermi GBM observation
  3. GRB 100522A: Swift XRT refined analysis
  4. GRB 100522A, Swift-BAT refined analysis
  5. GRB 100418A: CrAO optical observations
  6. GRB 100518A: GROND afterglow observation and photo-z
  7. GRB 100518A: Swift/UVOT Upper Limits
  8. GRB 100518A: Swift-XRT refined analysis
  9. GRB 100518A: optical afterglow decay
  10. GRB 100518A: BOOTES-3 optical observations
  11. Update to the configuration of the Fermi-LAT onboard GRB search
  12. GRB 100518A: Faulkes Telescope North Afterglow Candidate
  13. GRB 100513A: MITSuME Akeno Optical Observation
  14. GRB 100513A: EVLA radio observation
  15. GRB 100514A: optical afterglow confirmation
  16. GRB 100514A: Swift/UVOT Observations
  17. GRB 100514A: YNAO-GMG observations
  18. GRB 100514A: Swift XRT refined analysis
  19. GRB 100514A: MASTER-Net optical observations
  20. GRB 100514A: Swift-BAT refined analysis
  21. GRB 100514A: Faulkes Telescope South observations
  22. GRB 100513A: Faulkes Telescope South observations
  23. GRB 100513A: Swift/UVOT upper limits
  24. GRB 100513A, RIMOTS optical upper limits
  25. GRB 100513A: Swift XRT refined analysis
  26. GRB 100513A: Swift-BAT refined analysis
  27. GRB 100513A: Gemini/GMOS Spectroscopic Redshift
  28. GRB 100513A: Lick observations and R-band dropout
  29. GRB 100513A: PAIRITEL continued observations and confirmation of fading
  30. GRB 100513A: SARA-N Upper Limit
  31. GRB 100513A: PAIRITEL NIR afterglow candidate
  32. GRB 100510A: Fermi GBM detection/observation
  33. GRB 100511A: Super-LOTIS early observations
  34. Swift-BAT trigger 421695 is likely not astrophysical
  35. GRB100508A: Further Swift/UVOT Observations
  36. GRB100503A: Suzaku WAM observation of the prompt emission
  37. GRB 100508A: GROND Detection of the optical afterglow
  38. GRB 100508A: Swift-XRT Refined analysis
  39. GRB 100508A: Swift-BAT refined analysis
  40. GRB100508A: Swift/UVOT Detection of the Afterglow
  41. GRB 100508A: ROTSE-III Optical Limits
  42. GRB 100418A: Keck imaging
  43. GRB 100418A: RTT150 optical observations
  44. Swift-BAT refined analysis of trigger 421262
  45. GRB 100504A: Fermi GBM observation
  46. GRB 100504A: Swift/UVOT Observations
  47. GRB 100418A: Flattening of the Swift/UVOT Optical Light Curve
  48. GRB 100504A: Swift-XRT refined analysis
  49. GRB 100504A: GROND Upper limits
  50. GRB 100504A: Swift-BAT refined analysis
  51. GRB 100504A: SARA-South Upper Limit
  52. Swift-BAT trigger 421072 is not astrophyical
  53. INTEGRAL observations of Swift GRB trigger 421072
  54. GRB 100420A: EVLA radio observations
  55. GRB 100420A: Gemini discovery of infrared afterglow
  56. GRB 100423A: xinglong TNT optical upper limit
  57. GRB 100420A: Terskol optical upper limit
  58. GRB 100427A: Swift XRT and UVOT Upper Limits
  59. GRB 100427A: Fermi GBM detection
  60. GRB 100424a. Radio observations
  61. GRB 100418A: RTT150 optical observations
  62. GRB 100414A : EVLA Radio Detection
  63. GRB 100414A : WSRT Radio Detection
  64. Konus-Wind observation of GRB 100423A
  65. GRB 100423A: CrAO optical observations
  66. GRB 100418A: Terskol optical observations
  67. GRB 100424A: CrAO optical observations
  68. GRB 100424A: NIR Afterglow Confirmation
  69. GRB 100425A: Swift XRT refined analysis
  70. GRB 100424A: Gemini/NIRI H-band observations
  71. GRB100425A: Swift/UVOT Upper Limits
  72. GRB 100424A: Swift/UVOT Upper Limits
  73. GRB 100424A: Liverpool Telescope Upper Limits
  74. GRB 100425A: Swift-BAT refined analysis
  75. GRB 100425A: VLT/X-shooter redshift
  76. GRB 100425A: GROND afterglow observation
  77. GRB 100424A: Gemini/NIRI Candidate Afterglow
  78. GRB 100425A: candidate optical afterglow from the VLT
  79. GRB100423A: MITSuME optical upper limits
  80. GRB 100424A : Lulin early z'-band upper limit
  81. GRB 100424A: GROND Upper Limits
  82. GRB 100424A: PAIRITEL NIR Upper Limits
  83. GRB 100424A: Swift-XRT refined analysis
  84. GRB 100424A: WHT z-band observations
  85. GRB 100424A: NOT optical observations
  86. GRB 100424A, Swift-BAT refined analysis
  87. GRB 100424A: Prompt enhanced Swift-XRT position.
  88. GRB 100420A: GRT Optical Observation
  89. Swift-BAT refined analysis of trigger 420256
  90. GRB 100420A: Swift-BAT refined analysis
  91. GRB 100423A: Swift-BAT refined analysis
  92. Swift Trigger 420256: ROTSE-III Optical Limits
  93. GRB 100423A: Skynet/PROMPT Detections
  94. GRB 100423A: GROND discovery of afterglow
  95. Radio afterglow detection of GRB 100418A with the EVLA
  96. GRB 100414A: Radio Afterglow Detection with the Expanded VLA
  97. GRB 100418A: Continued PAIRITEL NIR Observations
  98. GRB 100418A: WSRT Radio Detection
  99. GRB100418A: REM possible afterglow detection
  100. GRB 100418A: Continuing Swift/UVOT Observations

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