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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"

16159 results found.

  1. GRB100807A: optical observation in CrAO
  2. GRB 100805A: optical observation in CrAO
  3. GRB 100805A: 2-nd epoch of SAO RAS optical observations
  4. GRB100807A: MITSuME optical upper limits
  5. GRB 100807A: P60 Optical Afterglow Discovery
  6. GRB 100807A: Swift/UVOT Upper Limits
  7. GRB 100805A: SAO RAS optical observations
  8. GRB 100807A: ROTSE-III Optical Limits
  9. GRB 100805A: IAC80 and 1.5m OSN optical observations
  10. GRB 100805A: Xinglong TNT optical observation
  11. GRB 100805A: ROTSE-III Optical detection
  12. GRB 100805A: Swift/UVOT Observations of the Optical Afterglow
  13. GRB 100805A: IAC80 BVR-band observations
  14. GRB 100805A: GRAS 002 optical observations
  15. GRB 100805A: I-band detection from 1.23m CAHA telescope.
  16. GRB 100805A: Liverpool Telescope afterglow observations
  17. GRB 100805A: Further P60 Monitoring
  18. GRB 100805A: P60 Optical Afterglow Candidate
  19. GRB 100805A: ROTSE-III Optical Limits
  20. GRB 100805A: Swift detection of a burst with an optical counterpart
  21. GRB 100728B: optical photometry of ISON-NM
  22. GRB 100713A: second epoch Maidanak optical observation
  23. GRB 100713A: CrAO optical limits
  24. GRB 100802A: NOT optical observation
  25. GRB100802A: MITSuME optical upper limits
  26. GRB 100802A: Swift/UVOT Possible Optical Afterglow
  27. GRB 100802A: ROTSE-III Optical Limits
  28. GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
  29. GRB 100725B: TELMA optical observation
  30. GRB 100728B - NOT optical observation
  31. GRB 100728B: Swift/UVOT Observations
  32. GRB 100728B: Continued KAIT observations
  33. GRB 100728A: GROND Detection of the NIR Afterglow Candidate
  34. GRB 100728A, Swift-BAT refined analysis
  35. GRB 100728B: optical detection
  36. GRB 100728B: Skynet/PROMPT Detections (correction)
  37. GRB 100728B: KAIT optical afterglow detection (correction)
  38. GRB 100728B: Swift detection of a burst with an optical counterpart
  39. GRB 100728A: KAIT optical afterglow detection
  40. GRB 100727A, Swift-BAT refined analysis
  41. GRB100727A: MOA optical upper limit
  42. GRB100725B: MITSuME optical upper limits
  43. GRB 100725A: GROND upper limits
  44. GRB 100725B: Swift/UVOT Upper Limits
  45. GRB 100725A: Swift/UVOT Upper Limits
  46. GRB 100724A: X-shooter redshift
  47. GRB 100614A: 10.4-m GTC deep-optical limit
  48. GRB 100718A: MASTER-Net optical prompt and alert observations
  49. GRB 100713A: optical observation in Maidanak
  50. GRB100713A: Swift/UVOT observations
  51. GRB 100713A: optical upper limit
  52. GRB 100713A: TNG optical observations
  53. GRB 100713A: TELMA and 1.5m OSN optical observations
  54. GRB 100704: Swift/UVOT Upper Limits
  55. GRB100704A: MOA optical upper limit
  56. Swift/UVOT observations of GRB100702A
  57. GRB 100702A: VLT optical observations
  58. GRB 100702: ROTSE-III Optical Limits
  59. GRB 100213B: Detection of Fading Optical Afterglow
  60. GRB 100628A: GROND optical/NIR observations of the host candidate
  61. GRB100628A : MOA optical upper limit
  62. GRB 090709A: Host galaxy detection
  63. GRB 100628A: Swift/UVOT Upper Limits
  64. GRB100628A: RTT150 optical observations
  65. GRB 100625A: Magellan near-IR Observations
  66. GRB 100614A: CrAO optical limit
  67. GRB 100625A: Swift/UVOT Upper Limits
  68. GRB100625A : MOA optical upper limit
  69. GRB 100418A: late time optical observations
  70. GRB 100621A MOA-II optical limit
  71. GRB 100621A: VLT/X-shooter redshift
  72. GRB 100621A: GROND observation of bright NIR afterglow
  73. GRB 100621A: ROTSE-III Optical Limits
  74. GRB 100606A: Optical Limits
  75. GRB 100619A: Swift/UVOT Upper Limits
  76. GRB 100614A: Gemini/NIRI Observations
  77. GRB 100614A: NOT optical upper limits
  78. GRB 100614A: MASTER-Net optical alert observations
  79. GRB 100615A: PAIRITEL NIR Upper Limits
  80. GRB 100614A: BOOTES-2/TELMA optical observations
  81. GRB 100614A: Liverpool Telescope Observations
  82. GRB 100606A: GROND observations
  83. Trigger 424161: Swift/BAT trigger on XTE J1946+274/GRO J1944+26
  84. Radio detection of GRB100418a with ATCA
  85. Swift detection of outburst from the SFXT IGR J18410-0535
  86. GRB 100111A: Maidanak optical observations
  87. GRB 100418A: Maidanak optical observations
  88. GRB 100513A: CrAO optical observations
  89. GRB 100514A: CrAO optical observations
  90. GRB 100526A: optical upper limit
  91. GRB 100528A: Faulkes Telescope North Detection
  92. GRB 100528A: NOT optical observation
  93. GRB 100526B: Swift/UVOT Upper Limits
  94. GRB 100526A: Swift/UVOT Upper Limits
  95. GRB 100526A: NOT optical upper limit
  96. GRB 100526A: MASTER-Net optical alert observations
  97. GRB 100418A: Subaru late-time optical imaging and spectroscopy
  98. GRB 100522A: GROND observations, upper limits
  99. Swift/UVOT observations of GRB100522A.
  100. GRB 100522A: BOOTES-2 optical limit

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