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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"

27392 results found.

  1. GRB 070412: NOT observations
  2. GRB 070411, Swift-BAT refined analysis
  3. GRB 070412: Swift detection of a burst
  4. GRB 070411: IAC80 optical observations
  5. GRB 070411 : Liverpool Telescope Observations
  6. GRB 070411: Swift detection of a burst with optical afterglow
  7. GRB 070406: Swift XRT team further analysis
  8. Suzaku ToO observation of SGR 1806-20
  9. GRB 070406: Astrometrically Refined XRT Position, Unfading Source
  10. GRB 070406, Swift-BAT refined analysis
  11. GRB 070406: Correction to the optical candidate in GCN6253
  12. GRB 070406: Gemini South Imaging and XRT analysis
  13. GRB070406: Swift UVOT observations
  14. GRB 070406: further analysis of NOT images.
  15. Short GRB 070406 - Possible Bright Host Galaxy
  16. GRB 070406: NOT observations
  17. GRB 070406: Optical candidate
  18. GRB 070406: SARA upper limit
  19. GRB 070406: Xinglong TNT optical Upper Limit
  20. GRB 070402: Suzaku WAM observation of the prompt emission
  21. GRB 070328: Suzaku WAM observation of the prompt emission
  22. UVOT observations of GRB070330
  23. GRB 070330, Swift-BAT refined analysis
  24. GRB 070330: TAROT La Silla observatory optical observations
  25. GRB 070330 - Watcher Observations
  26. GRB 070330: Swift detection of a burst
  27. GRB 070328: Swift/UVOT Upper Limits
  28. long burst from SGR 1806-20 detected on March 26
  29. GRB 070328: Swift/XRT Refined Analysis
  30. GRB 070328 : Suzaku ToO follow up starts
  31. GRB 070328, Swift-BAT refined analysis
  32. GRB 070328: Swift detection of a burst
  33. GRB 070311, deep optical photometry
  34. Short-Hard GRB 070209: PROMPT Observations
  35. GRB 070318: absorption-line redshift
  36. GRB070318: Swift UVOT continuing observations
  37. GRB 070318, Swift-BAT refined analysis
  38. GRB 070318: Swift detection of a burst with an optical afterglow
  39. GRB 070311: Late Central Engine Activity Optical Flare??
  40. VLA observation of GRB 070311
  41. GRB 070311: Optical observation.
  42. GRB 070306: possible emission-line redshift
  43. GRB 070311: SARA upper limit
  44. GRB 070309: variability of the XRT afterglow candidate
  45. GRB070311: FRAM early follow-up limit
  46. GRB 070311: P60 Observations
  47. GRB 070311: Swift/UVOT Upper Limits
  48. GRB 070311: MITSuME Okayama Optical Observation
  49. GRB 070311: Swift-XRT refined analysis
  50. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  51. GRB 070311: REM candidate afterglow
  52. GRB 070311: a long GRB detected by INTEGRAL
  53. GRB060901: Candidate optical afterglow
  54. GRB 070125: Chandra X-ray Confirmation of Jet Break
  55. GRB 070309: Swift/UVOT Upper Limits
  56. GRB 070306, optical observation
  57. Swift UVOT Finding Charts for GRB 070309
  58. GRB 070309: A long GRB detected by INTEGRAL
  59. GRB 070125: X-ray light curve analysis
  60. VLA observation of GRB 070306
  61. GRB 070306: NOT observations
  62. GRB 070306 Swift/UVOT refined analysis
  63. GRB 070306: IR observations and candidate afterglow
  64. GRB 070306, Swift-BAT refined analysis
  65. GRB 070306: XRT Team Refined Analysis
  66. GRB 070306: Optical and IR observations with KANATA
  67. GRB070306 - SDSS Pre-burst Observations
  68. GRB 070306: Swift detection of a burst
  69. GRB070227: Swift-XRT refined analysis
  70. GRB 060605 new redshift
  71. GRB 070125, deep late-time optical observation
  72. VLA observation of GRB 070224
  73. GRB 070227: Swift/UVOT Upper Limits
  74. GRB 070227: TAROT La Silla observatory optical observations
  75. GRB 070227, Swift-BAT refined analysis
  76. GRB 070227: Swift detection of a burst in ground analysis
  77. GRB 070224: Swift/UVOT Upper Limits
  78. VLA observation of GRB 070223
  79. VLA observation of GRB 070220
  80. GRB070224: Magellan Imaging Observations
  81. GRB 070224: WHT K-band imaging
  82. GRB 070224: MDM Observations
  83. GRB070224: Gemini Imaging Observations
  84. GRB 070224: SARA upper limit
  85. GRB070224: Swift-XRT Refined Analysis
  86. GRB 070224: optical afterglow candidate
  87. GRB 070224, Swift-BAT refined analysis
  88. GRB 070224: MASTER-Net refind analysis
  89. GRB 070224: MASTER-VWF-Kislovodsk observations
  90. GRB 070224: Swift detection of a burst
  91. GRB 070223: Optical observations
  92. GRB070223: Swift/UVOT refined analysis
  93. GRB 070223: Optical-IR observation with KANATA
  94. GRB 070223, Swift-BAT refined analysis
  95. GRB070223: MASTER-VWF-Kislovodsk observations
  96. GRB 070223: Swift-XRT Refined Analysis
  97. GRB070223 - SDSS Pre-Burst Observations
  98. GRB 070223: MDM Observations
  99. GRB070223: Swift burst
  100. GRB 070220: MITSuME Okayama Optical Observation

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