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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"

20960 results found.

  1. GRB 100414A : EVLA Radio Detection
  2. GRB 100414A : WSRT Radio Detection
  3. GRB 100423A: CrAO optical observations
  4. GRB 100418A: Terskol optical observations
  5. GRB 100424A: CrAO optical observations
  6. GRB 100424A: NIR Afterglow Confirmation
  7. GRB 100424A: Gemini/NIRI H-band observations
  8. GRB100425A: Swift/UVOT Upper Limits
  9. GRB 100424A: Swift/UVOT Upper Limits
  10. GRB 100425A: GROND afterglow observation
  11. GRB 100424A: Gemini/NIRI Candidate Afterglow
  12. GRB 100425A: candidate optical afterglow from the VLT
  13. GRB 100424A : Lulin early z'-band upper limit
  14. GRB 100424A: GROND Upper Limits
  15. GRB 100424A: PAIRITEL NIR Upper Limits
  16. GRB 100424A: WHT z-band observations
  17. GRB 100424A: NOT optical observations
  18. GRB 100418A: ROVOR optical measurements at 35 hours
  19. GRB 100418A: Possible Evidence for a Supernova
  20. Swift Trigger 420256: IAC80 R-band observations
  21. Swift Trigger 420256: BOOTES-2 observations
  22. GRB 100423A: GROND discovery of afterglow
  23. Radio afterglow detection of GRB 100418A with the EVLA
  24. GRB 100414A: Radio Afterglow Detection with the Expanded VLA
  25. GRB 100418A: Continued PAIRITEL NIR Observations
  26. GRB 100418A: WSRT Radio Detection
  27. GRB 100418A: Continuing Swift/UVOT Observations
  28. GRB 100418A: further GROND observations and light curve fit
  29. GRB 100418A: RTT150 optical observations
  30. GRB 100414A: CFHT optical observations
  31. GRB 100420A: Swift/UVOT Upper Limits
  32. GRB 100418A: SARA second epoch
  33. GRB 100420A: SARA Upper Limits
  34. GRB 100418A: RTT150 observations during the optical afterglow maximum
  35. GRB 100418A: optical observations
  36. GRB 100418A: MASTER-Net optical observations
  37. GRB 100418A: VLT optical observations
  38. GRB 100418A: SMA submm detection
  39. GRB 100418A PAIRITEL NIR Observations
  40. GRB 100418A: ROVOR optical afterglow detection
  41. GRB 100418A: Swift/UVOT Observations
  42. GRB 100418A: SARA observations
  43. GRB100414A: SAO RAS optical observations
  44. GRB 100418A: GROND observations; missing author list added
  45. GRB 100418A: GROND observations
  46. GRB 100418A: ROTSE-III Optical Limits
  47. GRB 100413A: Radio Afterglow Detection with the EVLA
  48. GRB 100414A: Swift/UVOT Observations
  49. GRB 100414A: GROND Detection of the Optical Afterglow
  50. GRB 100414A: Gemini-N candidate and redshift
  51. GRB 100414A: Palomar Transient Factory Observations
  52. GRB 100413B: Swift Confirmation of Burst
  53. GRB 100415A: MAXI/GSC detection of a probable GRB
  54. GRB 100413B : Swift detection of a burst
  55. GRB 100413A: GROND Upper limits
  56. GRB 100413A: Swift/UVOT Upper Limits
  57. GRB 100413A: Faulkes Telescope South observations
  58. GRB 100413A: SARA upper limit
  59. GRB 100413: xinglong TNT optical upper limit
  60. GRB 100413A: MASTER-Net optical observations
  61. GRB100401A: GROND Upper Limits
  62. INTEGRAL Alert n. 5995: MASTER-Net optical observations
  63. MASTER observations on the Swift second trigger on LS V +44 17
  64. GRB 100331B: GROND Upper limits
  65. Master-Net observations on the Swift trigger on LS V +44 17
  66. Swift/BAT trigger 417974 (GRB100401A): Swift/XRT observations
  67. GRB 100331B: BOOTES-3 observations
  68. GRB 100331B: Swift/UVOT Upper Limits
  69. INTEGRAL trigger 5994 (GRB100331A): Swift/XRT observations
  70. INTEGRAL trigger 5994 / GRB 100331A: GROND detection of a variable source
  71. GRB 100331A: BOOTES-3 observations
  72. GROND observations of GRB100316D/SN2010bh
  73. GRB 100324A: GROND observations
  74. GRB 100316D: Spectroscopic Discovery of a Supernova from Magellan
  75. SGR 1833-0832: Swift/UVOT Upper Limits
  76. SGR 1833-0832: Archival Chandra Observations
  77. Possible pulsation period in SGR 1833-0832
  78. Discovery of the Spin Period of SGR 1833-0832
  79. GRB 100316D: ATCA radio observations
  80. GRB 100319A: correction to GCN 10527
  81. GRB 100219A: MASTER-Net optical alert observations
  82. GRB 100316D: Possible Supernova
  83. GRB 100316D: Pre-burst emission measured by BAT
  84. GRB 100316D: Further Gemini observations
  85. GRB 100219A: optical upper limit
  86. GRB 100316A: optical observations in CrAO
  87. GRB 100316D: Swift/UVOT Observations
  88. GRB 100316D: Swift XRT enhanced position and further refined analysis
  89. GRB 100316C: GROND Detection of a Optical/NIR Afterglow Candidate
  90. GRB 100316D: GROND Detection of the Optical/NIR Afterglow Candidate
  91. GRB 100316D: Gemini/GMOS and VLT/X-shooter observations
  92. GRB 100316D: VLT/X-shooter observations
  93. GRB100316C: Swift/UVOT Upper Limits
  94. GRB 100316B: Swift/UVOT observations
  95. GRB 100316A: TAROT Calern observatory optical observations
  96. GRB 100316A: Swift-XRT refined analysis
  97. GRB100316A: Swift/UVOT Upper Limits
  98. GRB 100316C: BOOTES-3 observations
  99. GRB 100316B: VLT/X-shooter redshift
  100. GRB 100316B: Skynet/PROMPT Observations of Fading

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