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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"

16155 results found.

  1. GRB 070318: Swift detection of a burst with an optical afterglow
  2. GRB 070311: Late Central Engine Activity Optical Flare??
  3. GRB 070311: MDM Optical Monitoring
  4. GRB 070311: Tautenburg sees afterglow fading
  5. GRB 070311: Optical observation.
  6. GRB 070311: Optical Brightening
  7. GRB 070309: variability of the XRT afterglow candidate
  8. GRB 070311: MDM Optical Follow-up
  9. GRB 070311: RAPTOR Detection of Optical Emission
  10. GRB 070311: MDM Optical Detection
  11. GRB 070311: MITSuME Okayama Optical Observation
  12. GRB 070311: Swift-XRT refined analysis
  13. GRB 070311: REM candidate afterglow
  14. GRB060901: Candidate optical afterglow
  15. GRB 070125: Chandra X-ray Confirmation of Jet Break
  16. GRB 070306, optical observation
  17. GRB 070125: X-ray light curve analysis
  18. GRB 070306: ART-3 early optical and near infrared constraints
  19. GRB 070306: Optical and IR observations with KANATA
  20. GRB 070125, deep late-time optical observation
  21. GRB 070227: optical observations
  22. GRB 070223: Optical Observations
  23. GRB 070227: optical observations
  24. GRB 070227: TAROT La Silla observatory optical observations
  25. GRB 920925C: optical afterglow candidate
  26. GRB 070224: Optical afterglow confirmation
  27. GRB070224: Swift-XRT Astrometrically Corrected Position
  28. GRB070224: Magellan Imaging Observations
  29. GRB070224: Gemini Imaging Observations
  30. GRB 070224: optical afterglow candidate
  31. GRB 070223: Optical observations
  32. GRB 070223: Optical-IR observation with KANATA
  33. GRB 070223: Swift-XRT Refined Analysis
  34. GRB 070223: MDM Observations
  35. GRB 070220: MITSuME Okayama Optical Observation
  36. GRB 070220: ART-3 Optical and NIR limits
  37. GRB 070220: Observation with the KANATA 1.5m telescope
  38. GRB 070220 : Faulkes Telescope North optical limit
  39. GRB 070219: optical TNG observations
  40. GRB 070219: ROTSE-III Optical Limits
  41. GRB 070129: MDM I-band Detection
  42. GRB 070125: Break in Optical Decay
  43. GRB070208: optical observations
  44. GRB 070208: MARGE Optical Observations
  45. GRB 070208: RAPTOR detection of early afterglow onset
  46. GRB070208: Absorption and emission redshift from Gemini
  47. GRB 070208: MDM Optical Decay
  48. GRB 070208: Early IR detection and afterglow astrometry
  49. GRB 070208: ROTSE-III Optical Limits
  50. GRB 070208: MDM Observations
  51. GRB 070125 detection with CARMA
  52. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  53. GRB 070125: further AAVSO optical observations
  54. GRB 070125: optical observation
  55. GRB 070125: WSRT Radio Detection
  56. GRB070129: MITSuME optical observation
  57. GRB061217: MAGIC telescope GeV observation
  58. GRB 070129, Swift-BAT refined analysis of a particularly long
  59. GRB 070129: Xinglong TNT optical Upper Limit
  60. GRB 070125: further AAVSO optical observations
  61. GRB 070125: MITSuME Okayama optical observation
  62. GRB 070125: AAVSO optical observations
  63. GRB 070125: optical observations
  64. GRB 070125: WSRT Radio Observations
  65. GRB070125: Optical observation by Kanata
  66. Possible GRB 070126: Swift/UVOT Upper Limit
  67. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  68. GRB 070125: Xinglong TNT optical observations
  69. GRB 070125: Continued P60 Observations
  70. GRB070125: Swift-XRT Refined Analysis
  71. GRB 070125: P60 Optical Afterglow Candidate
  72. GRB 070110: optical break
  73. GRB 070110: Continued Detection and Request for Ground Followup
  74. GRB 070110 declared a "Burst of Interest" by Swift team
  75. GRB 070110: VLT absorption redshift
  76. GRB 070110: UVOT Observations of a Candidate Afterglow
  77. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  78. GRB 070110: Swift detection of a burst with a possible optical afterglow
  79. GRB070107: Swift/XRT refined analysis
  80. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  81. GRB 070103: TAROT Calern observatory optical observations
  82. GRB061222a: optical observations
  83. GRB 061210: Swift/XRT Astrometry Correction
  84. GRB 050826: MDM Redshift
  85. GRB 061222B: TAROT La Silla observatory early optical observations
  86. GRB 061218: TAROT La Silla observatory early optical observations
  87. GRB 061222A: MITSuME Akeno optical upper limits
  88. GRB 061222B: MITSuME Akeno optical upper limits
  89. GRB 061222A: Xinglong Optical Limit
  90. GRB061222A Swift/UVOT: Upper Limits
  91. GRB 061222B: Observation with the KANATA 1.5m telescope
  92. GRB061222B: Swift-XRT Refined Analysis
  93. GRB 061222A: Observation with the KANATA 1.5m telescope
  94. GRB 061222B: BOOTES-IR optical observations
  95. GRB 061222B: REM NIR/optical observations
  96. GRB 061222b, SMARTS optical/IR afterglow observations
  97. GRB 061222B: TAROT La Silla observatory optical observations
  98. GRB 061222b: optical afterglow
  99. GRB 061222A: Prompt ROTSE-III Optical Limits
  100. GRB 061217: Astrometry-Corrected XRT Position

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