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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"

28054 results found.

  1. GRB 070311: Late Central Engine Activity Optical Flare??
  2. VLA observation of GRB 070311
  3. GRB 070311: Optical observation.
  4. GRB 070306: possible emission-line redshift
  5. GRB 070311: SARA upper limit
  6. GRB 070309: variability of the XRT afterglow candidate
  7. GRB070311: FRAM early follow-up limit
  8. GRB 070311: P60 Observations
  9. GRB 070311: Swift/UVOT Upper Limits
  10. GRB 070311: MITSuME Okayama Optical Observation
  11. GRB 070311: Swift-XRT refined analysis
  12. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  13. GRB 070311: REM candidate afterglow
  14. GRB 070311: a long GRB detected by INTEGRAL
  15. GRB060901: Candidate optical afterglow
  16. GRB 070125: Chandra X-ray Confirmation of Jet Break
  17. GRB 070309: Swift/UVOT Upper Limits
  18. GRB 070306, optical observation
  19. Swift UVOT Finding Charts for GRB 070309
  20. GRB 070309: A long GRB detected by INTEGRAL
  21. GRB 070125: X-ray light curve analysis
  22. VLA observation of GRB 070306
  23. GRB 070306: NOT observations
  24. GRB 070306 Swift/UVOT refined analysis
  25. GRB 070306: IR observations and candidate afterglow
  26. GRB 070306, Swift-BAT refined analysis
  27. GRB 070306: XRT Team Refined Analysis
  28. GRB 070306: Optical and IR observations with KANATA
  29. GRB070306 - SDSS Pre-burst Observations
  30. GRB 070306: Swift detection of a burst
  31. GRB070227: Swift-XRT refined analysis
  32. GRB 060605 new redshift
  33. GRB 070125, deep late-time optical observation
  34. VLA observation of GRB 070224
  35. GRB 070227: Swift/UVOT Upper Limits
  36. GRB 070227: TAROT La Silla observatory optical observations
  37. GRB 070227, Swift-BAT refined analysis
  38. GRB 070227: Swift detection of a burst in ground analysis
  39. GRB 070224: Swift/UVOT Upper Limits
  40. VLA observation of GRB 070223
  41. VLA observation of GRB 070220
  42. GRB070224: Magellan Imaging Observations
  43. GRB 070224: WHT K-band imaging
  44. GRB 070224: MDM Observations
  45. GRB070224: Gemini Imaging Observations
  46. GRB 070224: SARA upper limit
  47. GRB070224: Swift-XRT Refined Analysis
  48. GRB 070224: optical afterglow candidate
  49. GRB 070224, Swift-BAT refined analysis
  50. GRB 070224: MASTER-Net refind analysis
  51. GRB 070224: MASTER-VWF-Kislovodsk observations
  52. GRB 070224: Swift detection of a burst
  53. GRB 070223: Optical observations
  54. GRB070223: Swift/UVOT refined analysis
  55. GRB 070223: Optical-IR observation with KANATA
  56. GRB 070223, Swift-BAT refined analysis
  57. GRB070223: MASTER-VWF-Kislovodsk observations
  58. GRB 070223: Swift-XRT Refined Analysis
  59. GRB070223 - SDSS Pre-Burst Observations
  60. GRB 070223: MDM Observations
  61. GRB070223: Swift burst
  62. GRB 070220: MITSuME Okayama Optical Observation
  63. GRB 070220 Swift-BAT Refined Analysis
  64. Swift/UVOT refined analysis of GRB070220
  65. GRB 070209: Swift XRT refined analysis
  66. GRB 070220: Swift-XRT Refined Analysis
  67. GRB 070220: Observation with the KANATA 1.5m telescope
  68. GRB 070219: Gemini Observations
  69. GRB 070220: Swift detection of a burst
  70. GRB070219: MASTER-VWF-Kislovodsk observations
  71. GRB 070219: Swift/UVOT Upper limits
  72. GRB 070219: I-band observations
  73. GRB 070219, Swift-BAT refined analysis
  74. GRB 070219: optical TNG observations
  75. GRB070219 - SDSS Pre-Burst Observations
  76. GRB 070219: Swift detection of a burst
  77. GRB 070125 observations with the GMRT
  78. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  79. GRB 070129: MDM I-band Detection
  80. GRB 070125: Break in Optical Decay
  81. GRB 070209: Swift XRT analysis
  82. GRB 070201: clarification on localization and Konus-Wind spectra
  83. IPN localization of very bright long hard GRB 070207
  84. GRB 070209, Swift-BAT refined analysis of the short hard burst
  85. GRB 070208: Swift XRT refined analysis
  86. GRB 070208, Swift-BAT refined analysis
  87. GRB070208 - SDSS Pre-Burst Observations
  88. GRB 070208: Early IR detection and afterglow astrometry
  89. GRB 070208: Swift detection of a burst
  90. GRB 070125 detection with CARMA
  91. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  92. GRB 070129: afterglow confirmation
  93. GRB070126: Swift-XRT Observation
  94. GRB 070129: Swift/UVOT Upper limits
  95. GRB 070125: optical observation
  96. GRB 070129, Swift-BAT refined analysis of a particularly long
  97. GRB 070129: Xinglong TNT optical Upper Limit
  98. GRB 070129: Swift-XRT Refined Analysis
  99. GRB 070129: VLT observations
  100. GRB 070125: An IR Point Source and an Apparent Host Galaxy

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