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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"

18676 results found.

  1. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  2. GRB061217: MAGIC telescope GeV observation
  3. GRB 070129, Swift-BAT refined analysis of a particularly long
  4. GRB 070129: Swift-XRT Refined Analysis
  5. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  6. GRB 070129: Swift detection of a burst
  7. GRB 070126: Swift/UVOT refined analysis
  8. GRB070126: Swift-XRT possible detection of an afterglow
  9. GRB 070125: UVOT Detection in Ultraviolet Filters
  10. GRB 070126, Swift-BAT refined analysis of a very faint burst
  11. GRB070124: Swift-XRT Observation
  12. Possible GRB 070126: Swift/UVOT Upper Limit
  13. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  14. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  15. GRB070125: Swift-XRT Refined Analysis
  16. GRB 070126?: Swift detection of a possible burst
  17. IPN-BAT localization of GRB070125 (very long duration, intense)
  18. IPN localization of GRB070124 (short duration, hard spectrum)
  19. Swift-BAT trigger 257213 is a Galactic Center transient
  20. GRB 070110: Continued Detection and Request for Ground Followup
  21. GRB 070110: Ep,i - Eiso correlation
  22. GRB 070110 declared a "Burst of Interest" by Swift team
  23. Further Retractions of previous Swift-BAT triggers
  24. Swift-BAT Trigger 255685 is not a GRB
  25. Trigger 255685: Swift detection of a possible burst
  26. GRB 070110: UVOT Observations of a Candidate Afterglow
  27. GRB070110: Swift XRT Team refined analysis
  28. GRB 070110, Swift-BAT refined analysis
  29. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  30. GRB 070110: Swift detection of a burst with a possible optical afterglow
  31. GRB070107: Swift/XRT refined analysis
  32. GRB 070107: Possible UVOT Afterglow
  33. GRB 070107, Swift-BAT refined analysis
  34. GRB 070107: Swift/XRT position
  35. GRB 070107: Swift detection of a burst
  36. GRB070103: APO SPIcam i' and z' limits
  37. GRB 070103: Swift/UVOT Upper limits
  38. GRB070103: Swift XRT refined analysis
  39. GRB 070103, Swift-BAT refined analysis
  40. GRB 070103: TAROT Calern observatory optical observations
  41. GRB 070103: Swift detection of a burst
  42. Retractions of previous Swift-BAT triggers
  43. Konus-Wind observation of GRB 061222A
  44. GRB 061210: Swift/XRT Astrometry Correction
  45. GRB 050826: MDM Redshift
  46. GRB 061222B, Swift-BAT refined analysis
  47. GRB061222A Swift/UVOT: Upper Limits
  48. GRB 061222B: Swift/UVOT Upper limits
  49. GRB061222B: Swift-XRT Refined Analysis
  50. GRB 061222B: BOOTES-IR optical observations
  51. GRB 061222B: SARA upper limit
  52. GRB 061222A: Swift-XRT refined analysis
  53. GRB 061222A, Swift-BAT refined analysis
  54. GRB 061222B: TAROT La Silla observatory optical observations
  55. GRB 061222B: Swift detection of a burst
  56. GRB 061222A: Prompt ROTSE-III Optical Limits
  57. GRB 061222: Swift detection of a burst
  58. GRB 061217: Astrometry-Corrected XRT Position
  59. GRB 061217, Candidate host galaxy
  60. GRB 061217 - Swift/XRT position correction
  61. GRB 061218: TAROT La Silla observatory optical observations
  62. GRB 061217: TAROT Calern observatory optical observations
  63. GRB 061218, Swift-BAT refined analysis
  64. Swift triggers (#251863) on a possible burst
  65. GRB061217: Swift/UVOT refined analysis.
  66. GRB 061217: optical observations at Calar Alto
  67. GRB061217 - Swift/XRT refined analysis
  68. GRB 061217, Further Swift-BAT refined analysis of the short hard burst
  69. GRB 061217, Swift-BAT refined analysis
  70. GRB 061217: ROTSE-III Optical Limits
  71. GRB 061217: Swift detection of a short hard burst
  72. GRB 061210: MDM Follow-up Observation
  73. GRB061210: Swift/UVOT observations
  74. Swift-BAT Trigger 250908 is a Cosmic Ray Shower event
  75. GRB 061210: Swift XRT analysis - Possible counterparts
  76. GRB 061210 : Faulkes North Telescope optical limit
  77. GRB 061214(?): ROTSE-III Optical Limits
  78. GRB 061214(?): Swift detection of a possible burst
  79. Swift/BAT trigger #250033 is due to a known source during loss of
  80. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  81. GRB 061213: MASTER-VWF-Kislovodsk observations
  82. GRB 061210: MDM Observation
  83. GRB 061210, Swift-BAT refined analysis of the SHB
  84. GRB 061210: Swift-BAT detection of a short burst
  85. Optical Afterglow observations of GRB 061126
  86. GRB061126: update on the Swift-XRT afterglow light curve
  87. Corrections for Swift/UVOT Exposure Times for GRBs 061110B and 061121
  88. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  89. GRB061126 : NMSU 1.0m observations
  90. GRB 061202: Swift XRT refined analysis
  91. GRB061202: FRAM early follow-up limit
  92. GRB061202 optical limit by "Pi of the Sky"
  93. Konus-Wind observation of GRB 061201
  94. GRB061202: Swift/UVOT Upper Limits
  95. GRB 061202, Swift-BAT refined analysis
  96. GRB 061202: Swift detection of a burst
  97. GRB 061201: Swift XRT Team refined analysis
  98. GRB 061201: Initial UVOT Observations
  99. GRB 061201, Swift-BAT refined analysis of the SHB
  100. GRB 061201: Swift detection of a short hard burst

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