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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"

26365 results found.

  1. long burst from SGR 1806-20 detected on March 26
  2. GRB 070328: Swift/XRT Refined Analysis
  3. GRB 070328 : Suzaku ToO follow up starts
  4. GRB 070328, Swift-BAT refined analysis
  5. GRB 070328: Swift detection of a burst
  6. GRB 070311, deep optical photometry
  7. Short-Hard GRB 070209: PROMPT Observations
  8. GRB 070318: absorption-line redshift
  9. GRB070318: Swift UVOT continuing observations
  10. GRB 070318, Swift-BAT refined analysis
  11. GRB 070318: Swift detection of a burst with an optical afterglow
  12. GRB 070311: Late Central Engine Activity Optical Flare??
  13. VLA observation of GRB 070311
  14. GRB 070311: Optical observation.
  15. GRB 070306: possible emission-line redshift
  16. GRB 070311: SARA upper limit
  17. GRB 070309: variability of the XRT afterglow candidate
  18. GRB070311: FRAM early follow-up limit
  19. GRB 070311: P60 Observations
  20. GRB 070311: Swift/UVOT Upper Limits
  21. GRB 070311: MITSuME Okayama Optical Observation
  22. GRB 070311: Swift-XRT refined analysis
  23. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  24. GRB 070311: REM candidate afterglow
  25. GRB 070311: a long GRB detected by INTEGRAL
  26. GRB060901: Candidate optical afterglow
  27. GRB 070125: Chandra X-ray Confirmation of Jet Break
  28. GRB 070309: Swift/UVOT Upper Limits
  29. GRB 070306, optical observation
  30. Swift UVOT Finding Charts for GRB 070309
  31. GRB 070309: A long GRB detected by INTEGRAL
  32. GRB 070125: X-ray light curve analysis
  33. VLA observation of GRB 070306
  34. GRB 070306: NOT observations
  35. GRB 070306 Swift/UVOT refined analysis
  36. GRB 070306: IR observations and candidate afterglow
  37. GRB 070306, Swift-BAT refined analysis
  38. GRB 070306: XRT Team Refined Analysis
  39. GRB 070306: Optical and IR observations with KANATA
  40. GRB070306 - SDSS Pre-burst Observations
  41. GRB 070306: Swift detection of a burst
  42. GRB070227: Swift-XRT refined analysis
  43. GRB 060605 new redshift
  44. GRB 070125, deep late-time optical observation
  45. VLA observation of GRB 070224
  46. GRB 070227: Swift/UVOT Upper Limits
  47. GRB 070227: TAROT La Silla observatory optical observations
  48. GRB 070227, Swift-BAT refined analysis
  49. GRB 070227: Swift detection of a burst in ground analysis
  50. GRB 070224: Swift/UVOT Upper Limits
  51. VLA observation of GRB 070223
  52. VLA observation of GRB 070220
  53. GRB070224: Magellan Imaging Observations
  54. GRB 070224: WHT K-band imaging
  55. GRB 070224: MDM Observations
  56. GRB070224: Gemini Imaging Observations
  57. GRB 070224: SARA upper limit
  58. GRB070224: Swift-XRT Refined Analysis
  59. GRB 070224: optical afterglow candidate
  60. GRB 070224, Swift-BAT refined analysis
  61. GRB 070224: MASTER-Net refind analysis
  62. GRB 070224: MASTER-VWF-Kislovodsk observations
  63. GRB 070224: Swift detection of a burst
  64. GRB 070223: Optical observations
  65. GRB070223: Swift/UVOT refined analysis
  66. GRB 070223: Optical-IR observation with KANATA
  67. GRB 070223, Swift-BAT refined analysis
  68. GRB070223: MASTER-VWF-Kislovodsk observations
  69. GRB 070223: Swift-XRT Refined Analysis
  70. GRB070223 - SDSS Pre-Burst Observations
  71. GRB 070223: MDM Observations
  72. GRB070223: Swift burst
  73. GRB 070220: MITSuME Okayama Optical Observation
  74. GRB 070220 Swift-BAT Refined Analysis
  75. Swift/UVOT refined analysis of GRB070220
  76. GRB 070209: Swift XRT refined analysis
  77. GRB 070220: Swift-XRT Refined Analysis
  78. GRB 070220: Observation with the KANATA 1.5m telescope
  79. GRB 070219: Gemini Observations
  80. GRB 070220: Swift detection of a burst
  81. GRB070219: MASTER-VWF-Kislovodsk observations
  82. GRB 070219: Swift/UVOT Upper limits
  83. GRB 070219: I-band observations
  84. GRB 070219, Swift-BAT refined analysis
  85. GRB 070219: optical TNG observations
  86. GRB070219 - SDSS Pre-Burst Observations
  87. GRB 070219: Swift detection of a burst
  88. GRB 070125 observations with the GMRT
  89. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  90. GRB 070129: MDM I-band Detection
  91. GRB 070125: Break in Optical Decay
  92. GRB 070209: Swift XRT analysis
  93. GRB 070201: clarification on localization and Konus-Wind spectra
  94. IPN localization of very bright long hard GRB 070207
  95. GRB 070209, Swift-BAT refined analysis of the short hard burst
  96. GRB 070208: Swift XRT refined analysis
  97. GRB 070208, Swift-BAT refined analysis
  98. GRB070208 - SDSS Pre-Burst Observations
  99. GRB 070208: Early IR detection and afterglow astrometry
  100. GRB 070208: Swift detection of a burst

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