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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"

4954 results found.

  1. Short-Hard GRB 070209: PROMPT Observations
  2. GRB 070318: Swift detection of a burst with an optical afterglow
  3. GRB 070306: IR observations and candidate afterglow
  4. GRB 070306: XRT Team Refined Analysis
  5. GRB070306 - SDSS Pre-burst Observations
  6. GRB 070227: optical observations
  7. GRB 070227: optical observations
  8. GRB070223: Swift burst
  9. GRB 070220: ART-3 Optical and NIR limits
  10. GRB 070220: Swift detection of a burst
  11. GRB 070208: MARGE Optical Observations
  12. GRB 070208: RAPTOR detection of early afterglow onset
  13. GRB 070208: MDM Optical Decay
  14. GRB 070208: Early IR detection and afterglow astrometry
  15. GRB 070208: Afterglow confirmation from P60
  16. GRB 070208: ROTSE-III Optical Limits
  17. GRB 070208: MDM Observations
  18. GRB 070208: Swift detection of a burst
  19. GRB 070125: optical observation
  20. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  21. GRB 070129: Swift detection of a burst
  22. GRB 070125: further AAVSO optical observations
  23. GRB 070125: AAVSO optical observations
  24. GRB 070125: Continued P60 Observations
  25. GRB070125: Swift-XRT Refined Analysis
  26. GRB 070125: P60 Optical Afterglow Candidate
  27. GRB 070110: Swift detection of a burst with a possible optical afterglow
  28. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  29. Retractions of previous Swift-BAT triggers
  30. GRB 061210: Swift/XRT Astrometry Correction
  31. GRB 061222A: MITSuME Akeno optical upper limits
  32. GRB 061222B: Swift detection of a burst
  33. GRB 061201: Correction to GCN 5944
  34. GRB 061201: Magellan Redshift of nearby Abell cluster
  35. GRB 061210: MDM Follow-up Observation
  36. GRB061210: Swift/UVOT observations
  37. GRB 060926: MASTER: discovery of the optical flare
  38. GRB 061202: Swift XRT refined analysis
  39. GRB 061202: Swift detection of a burst
  40. GRB 061122: GETS observation
  41. GRB 061126: optical observation
  42. GRB 061126: Swift/UVOT Observations
  43. GRB061121: optical observations
  44. GRB 061121: Swift/UVOT Observations
  45. GRB 061121: Swift-XRT Team Refined Analysis
  46. GRB061121, optical observation
  47. GRB 061121: Faulkes Telescope North Optical Observation
  48. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  49. GRB 061121: Swift detection of a bright burst with an optical counterpart
  50. GRB061110B: Optical observations at Crni Vrh
  51. GRB 061110A: Swift XRT refined analysis
  52. GRB 061110: Swift detection of a burst
  53. GRB 061109: Swift detection of a possible burst
  54. GRB 061102, XRT refined analysis
  55. GRB 061028: Swift detection of a burst
  56. GRB 061021: Swift/UVOT Observation
  57. GRB 061021: Swift detection of a burst
  58. GRB 060930: MARGE Optical Limits
  59. GRB 061007: Correction to GCN 5712
  60. GRB 061007: Swift detection of a burst with an optical counterpart
  61. GRB 060930: ROTSE-III Optical Limits
  62. GRB 060930: A long X-ray rich GRB detected by INTEGRAL
  63. GRB060929: Swift-XRT refined analysis.
  64. GRB 060927: Swift/UVOT Optical Observations
  65. GRB 060927: Xinglong TNT optical observations
  66. GRB 060926: MASTER: first minutes decay
  67. GRB 060926: MASTER OT alert observation
  68. GRB 060926: MASTER optical observation
  69. GRB060919: Swift/UVOT optical observations
  70. GRB 060919: TAROT optical observations
  71. GRB 060908: REM optical prompt observation
  72. GRB 060904b: SMARTS optical/IR afterglow observations
  73. GRB 060904B: RTT150 optical observations
  74. GRB060904A: Swift/UVOT optical observations
  75. GRB 060904B: Optical observations at Crni Vrh
  76. GRB 060904B: TAROT optical counterpart observations
  77. GRB 060904: TAROT optical observations
  78. 060901: Swift UVOT followup observations
  79. GRB 060901: SMARTS optical/IR observations
  80. Swift-BAT trigger 226614 is not a GRB
  81. GRB 060826(?): Swift detection of a possible burst
  82. GRB 060729, SMARTS optical/IR observations
  83. GRB 060814: Possible IR counterpart
  84. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  85. GRB 060729: An update on the Swift XRT and UVOT observations
  86. GRB 060805B: XRT Team Analysis
  87. GRB 060805B: X-ray Afterglow Detection, Spectral/Spatial/Temporal Properties
  88. IPN triangulation of GRB060805B
  89. GRB 060729 redshift
  90. GRB 060719: Swift detection of a burst
  91. GRB 060717: Swift detection of a burst
  92. GRB060714: optical observations
  93. GRB 060605: SkyNet Optical Limits
  94. GRB 060708: Swift detection of a burst with an UVOT countpart
  95. GRB 060614: SMARTS host galaxy observations
  96. GRB 060602A: Swift/XRT analysis
  97. GRB 060607B: Swift detection of a burst
  98. GRB 060607: Swift detection of a burst with bright optical counterpart
  99. GRB 060522: PROMPT Optical Limits
  100. GRB 060604: Swift detection of a burst with possible optical counterpart

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