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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"

36149 results found.

  1. GRB 070328: Swift/XRT Refined Analysis
  2. GRB 070328 : Suzaku ToO follow up starts
  3. GRB 070328, Swift-BAT refined analysis
  4. GRB 070328: Swift detection of a burst
  5. GRB070220: optical observations
  6. GRB070208: optical observations
  7. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  8. GRB 070311, deep optical photometry
  9. Short-Hard GRB 070209: PROMPT Observations
  10. GRB 070318: Gemini + Magellan spectra
  11. GRB 070318: absorption-line redshift
  12. GRB070318: Swift-XRT refined analysis
  13. GRB 070318: Swift/UVOT Continued Observations
  14. GRB 070318, Swift-BAT refined analysis
  15. IBAS Alert n. 4176: not a GRB
  16. GRB 070318: Swift detection of a burst with an optical afterglow
  17. GRB 070311: Late Central Engine Activity Optical Flare??
  18. GRB 070311: MDM Optical Monitoring
  19. VLA observation of GRB 070311
  20. GRB 070311: Tautenburg sees afterglow fading
  21. IBAS Alert n. 4169: not a GRB
  22. GRB 070311: Optical observation.
  23. GRB 070311: Optical Brightening
  24. GRB 070306: possible emission-line redshift
  25. GRB 070311: SARA upper limit
  26. GRB 070309: variability of the XRT afterglow candidate
  27. GRB 070311: MDM Optical Follow-up
  28. GRB 070311: RAPTOR Detection of Optical Emission
  29. GRB070311: FRAM early follow-up limit
  30. GRB 070311: P60 Observations
  31. GRB 070311: MDM Optical Detection
  32. GRB 070311: Swift/UVOT Upper Limits
  33. GRB 070311: MITSuME Okayama Optical Observation
  34. GRB 070311: Swift-XRT refined analysis
  35. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  36. GRB 070311: REM candidate afterglow
  37. GRB 070311: a long GRB detected by INTEGRAL
  38. GRB060901: Candidate optical afterglow
  39. GRB070309: Swift/XRT possible afterglow detection
  40. GRB 070125: Chandra X-ray Confirmation of Jet Break
  41. GRB 070309: Swift/UVOT Upper Limits
  42. GRB 070306, optical observation
  43. Swift UVOT Finding Charts for GRB 070309
  44. GRB 070309: A long GRB detected by INTEGRAL
  45. GRB 070125: X-ray light curve analysis
  46. VLA observation of GRB 070306
  47. IBAS Alert 4162: Not a GRB
  48. GRB 070306: NOT observations
  49. GRB 070306 Swift/UVOT refined analysis
  50. GRB070306: confirmation of near infrared afterglow
  51. GRB 070306: ART-3 early optical and near infrared constraints
  52. GRB 070306: IR observations and candidate afterglow
  53. GRB 070306, Swift-BAT refined analysis
  54. GRB 070306: XRT Team Refined Analysis
  55. GRB 070306: Optical and IR observations with KANATA
  56. GRB070306 - SDSS Pre-burst Observations
  57. GRB 070306: Swift detection of a burst
  58. GRB 070223: NIR observations at WHT
  59. GRB070227: Swift-XRT refined analysis
  60. GRB 060605 new redshift
  61. GRB 070125, deep late-time optical observation
  62. VLA observation of GRB 070224
  63. GRB 070227: optical observations
  64. GRB 070223: Optical Observations
  65. GRB 070227: optical observations
  66. GRB 070227: Swift/UVOT Upper Limits
  67. GRB 070227: TAROT La Silla observatory optical observations
  68. GRB 070227, Swift-BAT refined analysis
  69. GRB070227: possible X-ray afterglow detection
  70. GRB 070227: Swift detection of a burst in ground analysis
  71. GRB 920925C: optical afterglow candidate
  72. GRB 070224: Optical afterglow confirmation
  73. IBAS Alert n. 4144: not a GRB
  74. GRB 070224: Swift/UVOT Upper Limits
  75. VLA observation of GRB 070223
  76. VLA observation of GRB 070220
  77. GRB070224: Magellan Imaging Observations
  78. GRB 070224: WHT K-band imaging
  79. GRB 070224: MDM Observations
  80. GRB 070224: SARA upper limit
  81. GRB070224: Swift-XRT Refined Analysis
  82. GRB 070224: optical afterglow candidate
  83. GRB 070224, Swift-BAT refined analysis
  84. GRB 070224: MASTER-Net refind analysis
  85. GRB 070224: MASTER-VWF-Kislovodsk observations
  86. GRB 070224: MASTER observations
  87. GRB 070224: Swift detection of a burst
  88. GRB 070223: Optical observations
  89. GRB070223: Swift/UVOT refined analysis
  90. GRB 070223: Optical-IR observation with KANATA
  91. GRB 070223, Swift-BAT refined analysis
  92. GRB 070223: Swift-XRT Refined Analysis
  93. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  94. GRB070223 - SDSS Pre-Burst Observations
  95. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  96. GRB 070223: MDM Observations
  97. GRB070223: Swift burst
  98. Konus-Wind and Konus-A observations of GRB 070220
  99. GRB 070220: MITSuME Okayama Optical Observation
  100. GRB 070220: ART-3 Optical and NIR limits

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