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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"

45664 results found.

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

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