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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. GRB 070208: MDM Observations
  2. GRB 070208: Swift detection of a burst
  3. GRB 070125 detection with CARMA
  4. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  5. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  6. GRB 070129: afterglow confirmation
  7. GRB070124: Swift-XRT Follow-up Observation
  8. GRB070126: Swift-XRT Observation
  9. GRB 070125: further AAVSO optical observations
  10. GRB 070129: Swift/UVOT Upper limits
  11. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  12. GRB 070125: optical observation
  13. GRB 070125: WSRT Radio Detection
  14. GRB070129: MITSuME optical observation
  15. Radio detection of GRB 070125
  16. GRB061217: MAGIC telescope GeV observation
  17. GRB 070125: confirmation of pseudo-redshift
  18. GRB 070129, Swift-BAT refined analysis of a particularly long
  19. GRB 070129: Xinglong TNT optical Upper Limit
  20. GRB 070129: Swift-XRT Refined Analysis
  21. GRB 070129: VLT observations
  22. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  23. GRB 070129: Swift detection of a burst
  24. GRB 070126: Swift/UVOT refined analysis
  25. GRB 070125: further AAVSO optical observations
  26. GRB 070125: MITSuME Okayama optical observation
  27. Konus-Wind observation of GRB 070125
  28. GRB 070125: AAVSO optical observations
  29. GRB 070125: optical observations
  30. GRB 070126: VLT observations
  31. GRB070126: Swift-XRT possible detection of an afterglow
  32. GRB 070125: PROMPT detections
  33. GRB 070124: Suzaku WAM observation of the prompt emissions
  34. GRB 070125: WSRT Radio Observations
  35. GRB 070125: UVOT Detection in Ultraviolet Filters
  36. GRB 070126, Swift-BAT refined analysis of a very faint burst
  37. GRB070125: Optical observation by Kanata
  38. GRB070124: Swift-XRT Observation
  39. Possible GRB 070126: Swift/UVOT Upper Limit
  40. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  41. GRB 070125: Xinglong TNT optical observations
  42. GRB 070125: Continued P60 Observations
  43. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  44. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  45. GRB 070125: Lick 3m Spectroscopy
  46. GRB070125: Swift-XRT Refined Analysis
  47. GRB 070125: SARA detection in R
  48. GRB 070125: P60 Optical Afterglow Candidate
  49. GRB 070126?: Swift detection of a possible burst
  50. GRB070125 redshift request
  51. RHESSI Spectrum of GRB070125
  52. IPN-BAT localization of GRB070125 (very long duration, intense)
  53. Konus-Wind observation of short hard GRB 070124
  54. IPN localization of GRB070124 (short duration, hard spectrum)
  55. GRB 070110: optical break
  56. Swift-BAT trigger 257213 is a Galactic Center transient
  57. GRB 070110: Continued Detection and Request for Ground Followup
  58. GRB 050904: Second Epoch of HST/NICMOS Observations
  59. GRB 070110: Ep,i - Eiso correlation
  60. GRB 070107: Suzaku WAM observation of the prompt emission
  61. GRB 070110: VLT R-band photometry
  62. GRB 070110 declared a "Burst of Interest" by Swift team
  63. Further Retractions of previous Swift-BAT triggers
  64. Swift-BAT Trigger 255685 is not a GRB
  65. Trigger 255685: Swift detection of a possible burst
  66. GRB 070110: VLT absorption redshift
  67. GRB 070110: UVOT Observations of a Candidate Afterglow
  68. GRB070110: Swift XRT Team refined analysis
  69. GRB 070110, Swift-BAT refined analysis
  70. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  71. GRB 070110: Swift detection of a burst with a possible optical afterglow
  72. IBAS Alert n. 4047: Not a GRB
  73. GRB070107: Swift/XRT refined analysis
  74. GRB 070107: Possible UVOT Afterglow
  75. GRB 070107, Swift-BAT refined analysis
  76. GRB 070107: Swift/XRT position
  77. GRB 070107: Swift detection of a burst
  78. VLA observation of GRB 061222B
  79. VLA detection of GRB 061222A
  80. GRB070103: APO SPIcam i' and z' limits
  81. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  82. GRB070103: KPNO 4m+FLAMINGOS J limit
  83. GRB 070103: Swift/UVOT Upper limits
  84. GRB070103: Swift XRT refined analysis
  85. GRB 070103, Swift-BAT refined analysis
  86. GRB 070103: NOT observations
  87. GRB 070103: TAROT Calern observatory optical observations
  88. GRB 070103: Swift detection of a burst
  89. Retractions of previous Swift-BAT triggers
  90. GRB061222a: optical observations
  91. erratum : SDSS Pre-burst Observations of GRB061126
  92. Konus-Wind observation of GRB 061222A
  93. GRB 061210: Swift/XRT Astrometry Correction
  94. GRB 050826: MDM Redshift
  95. GRB 061222B: TAROT La Silla observatory early optical observations
  96. GRB 061218: TAROT La Silla observatory early optical observations
  97. GRB 061222A: MITSuME Akeno optical upper limits
  98. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  99. GRB 061222B: MITSuME Akeno optical upper limits
  100. GRB 061222A: Xinglong Optical Limit

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