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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"
  1. GRB070208: Absorption and emission redshift from Gemini
  2. GRB 070208: MDM Optical Decay
  3. GRB 070208, Swift-BAT refined analysis
  4. GRB070208 - SDSS Pre-Burst Observations
  5. GRB 070208: Early IR detection and afterglow astrometry
  6. GRB 070208: Afterglow confirmation from P60
  7. GRB070208: Faulkes Telescope North Afterglow Identification
  8. GRB 070208: ROTSE-III Optical Limits
  9. GRB 070208: MDM Observations
  10. GRB 070208: Swift detection of a burst
  11. GRB 070125 detection with CARMA
  12. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  13. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  14. GRB 070129: afterglow confirmation
  15. GRB070124: Swift-XRT Follow-up Observation
  16. GRB070126: Swift-XRT Observation
  17. GRB 070125: further AAVSO optical observations
  18. GRB 070129: Swift/UVOT Upper limits
  19. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  20. GRB 070125: optical observation
  21. GRB 070125: WSRT Radio Detection
  22. GRB070129: MITSuME optical observation
  23. Radio detection of GRB 070125
  24. GRB061217: MAGIC telescope GeV observation
  25. GRB 070125: confirmation of pseudo-redshift
  26. GRB 070129, Swift-BAT refined analysis of a particularly long
  27. GRB 070129: Xinglong TNT optical Upper Limit
  28. GRB 070129: Swift-XRT Refined Analysis
  29. GRB 070129: VLT observations
  30. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  31. GRB 070129: Swift detection of a burst
  32. GRB 070126: Swift/UVOT refined analysis
  33. GRB 070125: further AAVSO optical observations
  34. GRB 070125: MITSuME Okayama optical observation
  35. Konus-Wind observation of GRB 070125
  36. GRB 070125: AAVSO optical observations
  37. GRB 070125: optical observations
  38. GRB 070126: VLT observations
  39. GRB070126: Swift-XRT possible detection of an afterglow
  40. GRB 070125: PROMPT detections
  41. GRB 070124: Suzaku WAM observation of the prompt emissions
  42. GRB 070125: WSRT Radio Observations
  43. GRB 070125: UVOT Detection in Ultraviolet Filters
  44. GRB 070126, Swift-BAT refined analysis of a very faint burst
  45. GRB070125: Optical observation by Kanata
  46. GRB070124: Swift-XRT Observation
  47. Possible GRB 070126: Swift/UVOT Upper Limit
  48. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  49. GRB 070125: Xinglong TNT optical observations
  50. GRB 070125: Continued P60 Observations
  51. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  52. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  53. GRB 070125: Lick 3m Spectroscopy
  54. GRB070125: Swift-XRT Refined Analysis
  55. GRB 070125: SARA detection in R
  56. GRB 070125: P60 Optical Afterglow Candidate
  57. GRB 070126?: Swift detection of a possible burst
  58. GRB070125 redshift request
  59. RHESSI Spectrum of GRB070125
  60. IPN-BAT localization of GRB070125 (very long duration, intense)
  61. Konus-Wind observation of short hard GRB 070124
  62. IPN localization of GRB070124 (short duration, hard spectrum)
  63. GRB 070110: optical break
  64. Swift-BAT trigger 257213 is a Galactic Center transient
  65. GRB 070110: Continued Detection and Request for Ground Followup
  66. GRB 050904: Second Epoch of HST/NICMOS Observations
  67. GRB 070110: Ep,i - Eiso correlation
  68. GRB 070107: Suzaku WAM observation of the prompt emission
  69. GRB 070110: VLT R-band photometry
  70. GRB 070110 declared a "Burst of Interest" by Swift team
  71. Further Retractions of previous Swift-BAT triggers
  72. Swift-BAT Trigger 255685 is not a GRB
  73. Trigger 255685: Swift detection of a possible burst
  74. GRB 070110: VLT absorption redshift
  75. GRB 070110: UVOT Observations of a Candidate Afterglow
  76. GRB070110: Swift XRT Team refined analysis
  77. GRB 070110, Swift-BAT refined analysis
  78. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  79. GRB 070110: Swift detection of a burst with a possible optical afterglow
  80. IBAS Alert n. 4047: Not a GRB
  81. GRB070107: Swift/XRT refined analysis
  82. GRB 070107: Possible UVOT Afterglow
  83. GRB 070107, Swift-BAT refined analysis
  84. GRB 070107: Swift/XRT position
  85. GRB 070107: Swift detection of a burst
  86. VLA observation of GRB 061222B
  87. VLA detection of GRB 061222A
  88. GRB070103: APO SPIcam i' and z' limits
  89. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  90. GRB070103: KPNO 4m+FLAMINGOS J limit
  91. GRB 070103: Swift/UVOT Upper limits
  92. GRB070103: Swift XRT refined analysis
  93. GRB 070103, Swift-BAT refined analysis
  94. GRB 070103: NOT observations
  95. GRB 070103: TAROT Calern observatory optical observations
  96. GRB 070103: Swift detection of a burst
  97. Retractions of previous Swift-BAT triggers
  98. GRB061222a: optical observations
  99. erratum : SDSS Pre-burst Observations of GRB061126
  100. Konus-Wind observation of GRB 061222A

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