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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"

16161 results found.

  1. GRB 090423: P60 Observations
  2. GRB 090418A: R and I band observation
  3. GRB 090418B: RTT150 optical observations
  4. GRB 090418A: RTT150 optical observations
  5. GRB 080410: GAO 150cm telescope Optical Observation
  6. GRB 080408A: GAO 150cm telescope Optical Observation
  7. GRB 090417B: Optical observation
  8. GRB 090418A: optical observations
  9. GRB 090418A: Swift/UVOT Observations
  10. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  11. GRB 090419: Swift-BAT refined analysis
  12. VLA radio detection of GRB 090418
  13. GRB 090418A: ROTSE-III Refined Analysis
  14. GRB 090418: PAIRITEL NIR detection
  15. GRB 090418 Lick Redshift
  16. GRB 090418: ROTSE-III Confirmation of Optical Counterpart
  17. GRB 090418: Swift detection of a burst with optical afterglow
  18. GRB 090417B: MITSuME Okayama optical upper limits
  19. GRB090417B: Xinglong TNT optical upper limit
  20. GRB 090417B: optical observations
  21. GRB090417B: optical observations
  22. GRB 090410: MITSuME optical upper limits
  23. GRB090408 : TAOS optical observations
  24. GRB090408, RIMOTS optical upper limits
  25. GRB 090408: Xinglong TNT optical Upper Limit
  26. GRB 090408B: MASTER II-Kourovka optical observations
  27. GRB 090407: Swift UVOT Upper Limits
  28. GRB 090407: ROTSE-III Optical Limits
  29. GRB 090404: millimeter detection
  30. Swift/UVOT observations of GRB090404
  31. GRB 090404: optical observations at BOOTES-3 and 1.5-m OSN
  32. GRB 090404: Xinglong TNT optical Upper Limit
  33. GRB 090401B: Xinglong TNT optical Upper Limit
  34. GRB 090401B: Upper limits of MITSuME optical observation
  35. GRB090401B, RIMOTS optical upper limits
  36. GRB 090401B: NOT optical observations
  37. Swift/UVOT observations of GRB090401B
  38. Swift/UVOT observations of GRB090401B
  39. Swift/UVOT detection of GRB090401B
  40. GRB 090401B: Swift detection of a burst
  41. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  42. GRB 090323: Further TLS detections - a break?
  43. GRB 090328: Radio afterglow detection
  44. GRB 090328: BOOTES-3 optical observations
  45. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  46. GRB 090328: Gemini South Redshift
  47. GRB090323: Optical observations from NOT
  48. GRB 090328: Swift UVOT observations
  49. GRB 090323: WSRT Radio Detection
  50. GRB 090328: Updated position/optical afterglow candidate
  51. GRB 090323: Radio afterglow detection
  52. GRB 090320B: MASTER-Net prompt optical observations
  53. GRB 090323: RTT150 optical observations
  54. GRB 090323: Lick observations
  55. GRB 090323: Optical observation of xinglong TNT
  56. GRB 090323: UVOT Detection of Afterglow
  57. Further 15GHz observations of GRB090313
  58. GRB 090313: WSRT Radio Detection
  59. GRB 090313: VLT spectroscopy
  60. GRB090313: radio detection with the VLA
  61. GRB 090313, SMARTS optical/IR observations
  62. Further Swift/UVOT observations of GRB 090313
  63. GRB 090313: detection with CARMA in 3mm band
  64. GRB090305B: MASTER-net prompt optical short burst observations
  65. Radio detection of GRB090313
  66. GRB 090313: MITSuME Okayama observation
  67. GRB 090313: Additional Gemini-S photometry
  68. GRB 090313: WSRT Radio Observations
  69. GRB 090313: Light curve steepening
  70. GRB 090313: TAROT La Silla observatory optical detection
  71. GRB 090313: Gemini-S photometry
  72. GRB 090313: Zadko Telescope observations
  73. GRB 090313 - PAIRITEL NIR detections
  74. GRB 090313: Gemini-S redshift
  75. GRB 090313 optical observations
  76. GRB 090313: Ongoing plateau phase
  77. GRB 090313: Swift-XRT refined analysis
  78. GRB 090313: Swift/UVOT upper limits
  79. GRB 090313: Faulkes Telescope North observations
  80. GRB 090313: Sustained optical brightness (correction)
  81. GRB 090313: Sustained optical brightness
  82. GRB 090313: SDSS object underlying the optical afterglow position
  83. GRB 090309A: GROND upper limits
  84. GRB 090307A: TAROT Calern observatory optical observations
  85. GRB 090309: Swift/UVOT Upper Limits
  86. GRB 090308: Swift/UVOT Upper Limits
  87. GRB 090307: GROND Upper Limits
  88. Radio observation of GRB 090201 with ATCA
  89. Radio observation of GRB 081226a with ATCA
  90. Radio observation of GRB 081007 with ATCA
  91. GRB 090305: Swift-XRT refined analysis
  92. GRB 090305, Swift-BAT refined analysis
  93. GRB 090305: Magellan confirmation of the optical afterglow
  94. GRB090305: GMOS-S Candidate Optical Afterglow
  95. GRB 090205: VLT optical decay
  96. GRB 090205: Swift/UVOT Upper Limits
  97. GRB 090205: VLT refined redshift
  98. GRB 090205: Swift burst of interest
  99. GRB 090205: VLT spectroscopic redshift
  100. GRB090201: Swift UVOT upper limits

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