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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"

27415 results found.

  1. GRB 070219, Swift-BAT refined analysis
  2. GRB 070219: Liverpool Telescope Observations
  3. GRB 070219: ROTSE-III Optical Limits
  4. GRB070219 - SDSS Pre-Burst Observations
  5. GRB 070219: Swift detection of a burst
  6. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  7. Swift-BAT trigger 260304 is NOT a burst or transient
  8. GRB 070209: Swift XRT analysis
  9. IPN localization of very bright long hard GRB 070207
  10. IPN localization of very intense short GRB 070201
  11. GRB 070209, Swift-BAT refined analysis of the short hard burst
  12. GRB 070209: Swift detection of a short hard burst
  13. GRB 070208: Swift XRT refined analysis
  14. GRB 070208: RAPTOR detection of early afterglow onset
  15. GRB 070208, Swift-BAT refined analysis
  16. GRB 070208: Early IR detection and afterglow astrometry
  17. GRB070208: Faulkes Telescope North Afterglow Identification
  18. GRB 070208: ROTSE-III Optical Limits
  19. GRB 070208: MDM Observations
  20. GRB 070208: Swift detection of a burst
  21. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  22. GRB070126: Swift-XRT Observation
  23. GRB 070129: Swift/UVOT Upper limits
  24. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  25. GRB070129: MITSuME optical observation
  26. GRB061217: MAGIC telescope GeV observation
  27. GRB 070129, Swift-BAT refined analysis of a particularly long
  28. GRB 070129: Swift-XRT Refined Analysis
  29. GRB 070129: Swift detection of a burst
  30. GRB 070126: Swift/UVOT refined analysis
  31. GRB 070126: VLT observations
  32. GRB070126: Swift-XRT possible detection of an afterglow
  33. GRB 070125: UVOT Detection in Ultraviolet Filters
  34. GRB 070126, Swift-BAT refined analysis of a very faint burst
  35. GRB070124: Swift-XRT Observation
  36. Possible GRB 070126: Swift/UVOT Upper Limit
  37. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  38. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  39. GRB070125: Swift-XRT Refined Analysis
  40. GRB 070126?: Swift detection of a possible burst
  41. IPN-BAT localization of GRB070125 (very long duration, intense)
  42. Konus-Wind observation of short hard GRB 070124
  43. Swift-BAT trigger 257213 is a Galactic Center transient
  44. GRB 070110: Continued Detection and Request for Ground Followup
  45. GRB 070110: Ep,i - Eiso correlation
  46. Further Retractions of previous Swift-BAT triggers
  47. Swift-BAT Trigger 255685 is not a GRB
  48. Trigger 255685: Swift detection of a possible burst
  49. GRB 070110: UVOT Observations of a Candidate Afterglow
  50. GRB070110: Swift XRT Team refined analysis
  51. GRB 070110, Swift-BAT refined analysis
  52. GRB 070110: Swift detection of a burst with a possible optical afterglow
  53. IBAS Alert n. 4047: Not a GRB
  54. GRB070107: Swift/XRT refined analysis
  55. GRB 070107: Possible UVOT Afterglow
  56. GRB 070107, Swift-BAT refined analysis
  57. GRB 070107: Swift/XRT position
  58. GRB 070107: Swift detection of a burst
  59. GRB070103: APO SPIcam i' and z' limits
  60. GRB 070103: Swift/UVOT Upper limits
  61. GRB070103: Swift XRT refined analysis
  62. GRB 070103, Swift-BAT refined analysis
  63. GRB 070103: TAROT Calern observatory optical observations
  64. GRB 070103: Swift detection of a burst
  65. Retractions of previous Swift-BAT triggers
  66. Konus-Wind observation of GRB 061222A
  67. GRB 050826: MDM Redshift
  68. GRB 061222B: TAROT La Silla observatory early optical observations
  69. GRB 061218: TAROT La Silla observatory early optical observations
  70. GRB 061222A: MITSuME Akeno optical upper limits
  71. GRB 061222B: MITSuME Akeno optical upper limits
  72. GRB 061222B, Swift-BAT refined analysis
  73. GRB061222A Swift/UVOT: Upper Limits
  74. GRB 061222B: Swift/UVOT Upper limits
  75. GRB061222B: Swift-XRT Refined Analysis
  76. GRB 061222B: BOOTES-IR optical observations
  77. GRB 061222B: SARA upper limit
  78. GRB 061222A: Swift-XRT refined analysis
  79. GRB 061222A, Swift-BAT refined analysis
  80. GRB 061222B: TAROT La Silla observatory afterglow observation
  81. GRB 061222B: TAROT La Silla observatory optical observations
  82. GRB 061222B: Swift detection of a burst
  83. GRB 061222A: Prompt ROTSE-III Optical Limits
  84. GRB 061222: Swift detection of a burst
  85. GRB 061218: TAROT La Silla observatory optical observations
  86. GRB 061217: TAROT Calern observatory optical observations
  87. GRB 061218: TORTOREM optical upper limits
  88. GRB 061218, Swift-BAT refined analysis
  89. GRB 061218: REM prompt observations
  90. Swift triggers (#251863) on a possible burst
  91. GRB 061217, SMARTS optical observations
  92. GRB061217: Swift/UVOT refined analysis.
  93. GRB061217 - Swift/XRT refined analysis
  94. GRB 061217, Further Swift-BAT refined analysis of the short hard burst
  95. GRB 061217, Swift-BAT refined analysis
  96. GRB 061217: REM prompt observations
  97. GRB 061217: ROTSE-III Optical Limits
  98. GRB 061217: Swift detection of a short hard burst
  99. GRB 061210: MDM Follow-up Observation
  100. GRB061210: Swift/UVOT observations

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