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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"

14847 results found.

  1. GRB 070612A: SARA detection of possible OT
  2. GRB 070612B: Swift detection of a burst
  3. GRB 070612: Swift detection of a burst
  4. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  5. GRB 070610: TLS RRM sees flaring behaviour - Galactic transient?
  6. GRB 070611: Swift/UVOT Observations
  7. GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
  8. GRB 070611: Swift detection of a burst
  9. GRB 070610: Swift detection of a burst
  10. GRB 070419A, deep LBT photometry and possible supernova detection
  11. GRB 070531: Swift detection of a burst
  12. GRB 070529: Swift detection of a burst with an optical aterglow
  13. GRB 070412: Deep Keck imaging
  14. GRB070521: Second Epoch Gemini Imaging
  15. GRB 070521: Subaru observations and possible host detection
  16. GRB 070521: Swift detection of a burst
  17. GRB 070520B: Swift detection of a burst
  18. GRB 070520: Swift detection of a burst
  19. GRB 070518: Swift detection of a burst with optical afterglow
  20. GRB 070517: Swift detection of a burst
  21. GRB 070509: objects inside XRT error circle
  22. GRB 070510: Swift detection of a possible burst
  23. GRB 070509: Swift detection of a burst
  24. GRB070508: Swift/UVOT Observations
  25. GRB 070508: Optical afterglow detection
  26. GRB 070508: REM observations
  27. GRB 070508: Swift detection of an intense burst with an optical counterpart
  28. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  29. GRB 070506: Swift detection of a burst with optical afterglow
  30. GRB 070412, deep LBT imaging
  31. GRB070429B: VLT observations
  32. GRB070429B: possible host galaxy detection
  33. GRB 070429B: Swift detection of a short burst
  34. GRB 070429: Swift detection of a burst
  35. GRB 070427: Swift detection of a burst
  36. GRB 070411, further deep LBT photometry
  37. GRB070419A: Kuiper Optical detection
  38. GRB 070420: optical rebrightening observed at Mt. John
  39. GRB070420: Swift UVOT continuing observations
  40. GRB 070420: Swift detection of a burst with optical afterglow
  41. GRB 070419A: RAPTOR Detection of Early Emission
  42. GRB 070419B: optical afterglow confirmation
  43. GRB 070411: Deep VLT detection
  44. GRB 070419A: SARA observations
  45. GRB 070419B optical afterglow candidate
  46. GRB 070419B: optical afterglow candidate
  47. Infrared detection of GRB070419A with UKIRT
  48. GRB 070419B: Swift detection of a burst
  49. GRB 070419 optical afterglow candidate
  50. GRB 070419: Swift detection of a burst
  51. Trigger 276045: Swift detection of a possible burst
  52. GRB 070406: Swift XRT refined analysis
  53. GRB 070412: further NOT observations
  54. GRB 070412: Gemini/GMOS afterglow candidate
  55. GRB 070412: NOT observations
  56. GRB 070412: Swift detection of a burst
  57. GRB 070411: ROTSE-III Detection of Optical Counterpart
  58. GRB 070411: Swift detection of a burst with optical afterglow
  59. GRB 070406: Swift XRT team further analysis
  60. GRB 070406: Swift detection of a burst
  61. UVOT observations of GRB070330
  62. GRB 070330: Swift detection of a burst
  63. GRB 070328: Swift detection of a burst
  64. GRB 070318: Swift detection of a burst with an optical afterglow
  65. GRB 070311: Tautenburg sees afterglow fading
  66. GRB 070311: RAPTOR Detection of Optical Emission
  67. GRB 070311: MDM Optical Detection
  68. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  69. GRB070309: Swift/XRT possible afterglow detection
  70. GRB 070125: Chandra X-ray Confirmation of Jet Break
  71. GRB 070306: NOT observations
  72. GRB 070306: Swift detection of a burst
  73. GRB 070125, deep late-time optical observation
  74. GRB070227: possible X-ray afterglow detection
  75. GRB 070227: Swift detection of a burst in ground analysis
  76. GRB 920925C: optical afterglow candidate
  77. GRB 070224: Swift detection of a burst
  78. GRB 070223: Optical observations
  79. GRB 070220: Swift detection of a burst
  80. GRB 070219: Liverpool Telescope Observations
  81. GRB 070219: Swift detection of a burst
  82. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  83. GRB 070129: MDM I-band Detection
  84. GRB 070209: Swift detection of a short hard burst
  85. GRB 070208: RAPTOR detection of early afterglow onset
  86. GRB 070208: Early IR detection and afterglow astrometry
  87. GRB 070208: Swift detection of a burst
  88. GRB 070125 detection with CARMA
  89. GRB 070125: WSRT Radio Detection
  90. Radio detection of GRB 070125
  91. GRB 070129: Swift detection of a burst
  92. GRB 070125: further AAVSO optical observations
  93. GRB070126: Swift-XRT possible detection of an afterglow
  94. GRB 070125: UVOT Detection in Ultraviolet Filters
  95. GRB 070125: SARA detection in R
  96. GRB 070126?: Swift detection of a possible burst
  97. IPN-BAT localization of GRB070125 (very long duration, intense)
  98. GRB 070110: Continued Detection and Request for Ground Followup
  99. GRB 070110 declared a "Burst of Interest" by Swift team
  100. Further Retractions of previous Swift-BAT triggers

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