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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"

28074 results found.

  1. GRB 100420A: Terskol optical upper limit
  2. GRB 100427A: Swift XRT and UVOT Upper Limits
  3. GRB 100427A: Fermi GBM detection
  4. GRB 100424a. Radio observations
  5. GRB 100418A: RTT150 optical observations
  6. GRB 100414A : EVLA Radio Detection
  7. GRB 100414A : WSRT Radio Detection
  8. GRB 100423A: CrAO optical observations
  9. GRB 100418A: Terskol optical observations
  10. GRB 100424A: CrAO optical observations
  11. GRB 100424A: NIR Afterglow Confirmation
  12. GRB 100425A: Swift XRT refined analysis
  13. GRB 100424A: Gemini/NIRI H-band observations
  14. GRB100425A: Swift/UVOT Upper Limits
  15. GRB 100424A: Swift/UVOT Upper Limits
  16. GRB 100424A: Liverpool Telescope Upper Limits
  17. GRB 100425A: Enhanced Swift-XRT position
  18. GRB 100425A: VLT/X-shooter redshift
  19. GRB 100425A: GROND afterglow observation
  20. GRB 100424A: Gemini/NIRI Candidate Afterglow
  21. GRB 100424A: D50 optical limits
  22. GRB 100425A: candidate optical afterglow from the VLT
  23. GRB100424A: MITSuME optical upper limits
  24. GRB100423A: MITSuME optical upper limits
  25. GRB 100424A : Lulin early z'-band upper limit
  26. GRB 100424A: GROND Upper Limits
  27. GRB 100424A: PAIRITEL NIR Upper Limits
  28. GRB 100424A: Swift-XRT refined analysis
  29. GRB 100425A: Swift detection of a burst
  30. GRB 100424A: WHT z-band observations
  31. GRB 100424A: NOT optical observations
  32. GRB 100424A: Enhanced Swift-XRT position
  33. GRB 100424A: Prompt enhanced Swift-XRT position.
  34. GRB 100424A: Swift detection of a burst
  35. GRB 100420A: GRT Optical Observation
  36. GRB 100418A: ROVOR optical measurements at 35 hours
  37. Swift-BAT refined analysis of trigger 420256
  38. GRB 100418A: Possible Evidence for a Supernova
  39. GRB 100423B: Fermi GBM detection
  40. Trigger 420256: Swift detection of a possible GRB
  41. GRB 100423A: Skynet/PROMPT Detections
  42. GRB 100423A: GROND discovery of afterglow
  43. GRB 100423A: Swift detection of a burst
  44. Radio afterglow detection of GRB 100418A with the EVLA
  45. GRB 100414A: Radio Afterglow Detection with the Expanded VLA
  46. GRB 100418A: Continued PAIRITEL NIR Observations
  47. GRB 100418A: WSRT Radio Detection
  48. GRB100418A: REM possible afterglow detection
  49. GRB 100418A: Continuing Swift/UVOT Observations
  50. GRB 100418A: further GROND observations and light curve fit
  51. GRB 100418A: RTT150 optical observations
  52. GRB100420A: MITSuME optical upper limits
  53. GRB 100414A: CFHT optical observations
  54. GRB 100420A: Swift/UVOT Upper Limits
  55. GRB 100420A: XRT refined analysis
  56. GRB 100420A: Enhanced Swift-XRT position
  57. GRB 100418A: SARA second epoch
  58. GRB 100420A: SARA Upper Limits
  59. GRB 100418A: RTT150 observations during the optical afterglow maximum
  60. GRB 100418A: optical observations
  61. GRB 100418A: MASTER-Net optical observations
  62. GRB 100414A: Confirmation of the X-ray afterglow
  63. GRB 100418A: VLT optical observations
  64. GRB 100418A: SMA submm detection
  65. GRB 100420A: ROTSE-III Optical Limits
  66. GRB 100420A: Swift detection of a burst
  67. GRB 100418A PAIRITEL NIR Observations
  68. GRB 100418A: ROVOR optical afterglow detection
  69. GRB 100418A: Swift/UVOT Observations
  70. GRB 100413A: GMRT observation of radio afterglow
  71. GRB 100418A: Swift-XRT Refined Analysis
  72. GRB 100418A: host galaxy detection in the SDSS
  73. GRB 100418A: SARA observations
  74. GRB 100418A: GROND observations; missing author list added
  75. GRB 100418A: GROND observations
  76. GRB 100418A: Enhanced Swift-XRT position
  77. GRB 100418A: ROTSE-III Optical Limits
  78. GRB 100418A: Swift detection of a burst with a possible optical afterglow
  79. GRB 100413A: Radio Afterglow Detection with the EVLA
  80. GRB 100414A: GROND Detection of the Optical Afterglow
  81. GRB 100414A: Gemini-N candidate and redshift
  82. GRB 100414A: Enhanced Swift-XRT position of candidate afterglow
  83. GRB 100414A: Palomar Transient Factory Observations
  84. GRB 100413B: Swift Confirmation of Burst
  85. GRB 100414A: Swift-XRT detection of a possible X-ray afterglow
  86. GRB 100415A: MAXI/GSC detection of a probable GRB
  87. GRB 100414A: Fermi GBM detection
  88. GRB100414A: Fermi LAT detection
  89. GRB 100413B : Swift detection of a burst
  90. GRB 100413A: GROND Upper limits
  91. GRB 100413A: Swift/UVOT Upper Limits
  92. GRB 100413A: Faulkes Telescope South observations
  93. Tentative redshift of GRB100413A from X-ray data
  94. GRB 100413A: SARA upper limit
  95. GRB 100413A: Swift-XRT Refined Analysis
  96. GRB 100413A: Enhanced Swift-XRT position
  97. GRB 100413: xinglong TNT optical upper limit
  98. GRB 100413A: MASTER-Net optical observations
  99. GRB 100413A: Swift detection of a burst
  100. Trigger 419015 is probably not a GRB

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