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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 070125 observations with the GMRT
  2. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  3. Swift-BAT trigger 260304 is NOT a burst or transient
  4. GRB 060927: PROMPT Observations
  5. GRB 070201: Correction to GCN 6094
  6. GRB 070129: MDM I-band Detection
  7. GRB 070125: Break in Optical Decay
  8. GRB 070209: Swift XRT analysis
  9. GRB 070201: clarification on localization and Konus-Wind spectra
  10. GRB070208: optical observations
  11. GRB 070201: IPN constraints and nearby galaxies
  12. GRB 070201: Proximity of IPN annulus to M31
  13. GRB 070208: MARGE Optical Observations
  14. IPN localization of very bright long hard GRB 070207
  15. IPN localization of very intense short GRB 070201
  16. GRB 070209, Swift-BAT refined analysis of the short hard burst
  17. GRB 070209: Swift detection of a short hard burst
  18. GRB 070208: Swift XRT refined analysis
  19. GRB 070208: RAPTOR detection of early afterglow onset
  20. GRB070208: Absorption and emission redshift from Gemini
  21. GRB 070208: MDM Optical Decay
  22. GRB 070208, Swift-BAT refined analysis
  23. GRB070208 - SDSS Pre-Burst Observations
  24. GRB 070208: Early IR detection and afterglow astrometry
  25. GRB 070208: Afterglow confirmation from P60
  26. GRB070208: Faulkes Telescope North Afterglow Identification
  27. GRB 070208: ROTSE-III Optical Limits
  28. GRB 070208: MDM Observations
  29. GRB 070208: Swift detection of a burst
  30. GRB 070125 detection with CARMA
  31. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  32. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  33. GRB 070129: afterglow confirmation
  34. GRB070124: Swift-XRT Follow-up Observation
  35. GRB070126: Swift-XRT Observation
  36. GRB 070125: further AAVSO optical observations
  37. GRB 070129: Swift/UVOT Upper limits
  38. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  39. GRB 070125: optical observation
  40. GRB 070125: WSRT Radio Detection
  41. GRB070129: MITSuME optical observation
  42. Radio detection of GRB 070125
  43. GRB061217: MAGIC telescope GeV observation
  44. GRB 070125: confirmation of pseudo-redshift
  45. GRB 070129, Swift-BAT refined analysis of a particularly long
  46. GRB 070129: Xinglong TNT optical Upper Limit
  47. GRB 070129: Swift-XRT Refined Analysis
  48. GRB 070129: VLT observations
  49. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  50. GRB 070129: Swift detection of a burst
  51. GRB 070126: Swift/UVOT refined analysis
  52. GRB 070125: further AAVSO optical observations
  53. GRB 070125: MITSuME Okayama optical observation
  54. Konus-Wind observation of GRB 070125
  55. GRB 070125: AAVSO optical observations
  56. GRB 070125: optical observations
  57. GRB 070126: VLT observations
  58. GRB070126: Swift-XRT possible detection of an afterglow
  59. GRB 070125: PROMPT detections
  60. GRB 070124: Suzaku WAM observation of the prompt emissions
  61. GRB 070125: WSRT Radio Observations
  62. GRB 070125: UVOT Detection in Ultraviolet Filters
  63. GRB 070126, Swift-BAT refined analysis of a very faint burst
  64. GRB070125: Optical observation by Kanata
  65. GRB070124: Swift-XRT Observation
  66. Possible GRB 070126: Swift/UVOT Upper Limit
  67. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  68. GRB 070125: Xinglong TNT optical observations
  69. GRB 070125: Continued P60 Observations
  70. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  71. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  72. GRB 070125: Lick 3m Spectroscopy
  73. GRB070125: Swift-XRT Refined Analysis
  74. GRB 070125: SARA detection in R
  75. GRB 070125: P60 Optical Afterglow Candidate
  76. GRB 070126?: Swift detection of a possible burst
  77. GRB070125 redshift request
  78. RHESSI Spectrum of GRB070125
  79. IPN-BAT localization of GRB070125 (very long duration, intense)
  80. Konus-Wind observation of short hard GRB 070124
  81. IPN localization of GRB070124 (short duration, hard spectrum)
  82. GRB 070110: optical break
  83. Swift-BAT trigger 257213 is a Galactic Center transient
  84. GRB 070110: Continued Detection and Request for Ground Followup
  85. GRB 050904: Second Epoch of HST/NICMOS Observations
  86. GRB 070110: Ep,i - Eiso correlation
  87. GRB 070107: Suzaku WAM observation of the prompt emission
  88. GRB 070110: VLT R-band photometry
  89. GRB 070110 declared a "Burst of Interest" by Swift team
  90. Further Retractions of previous Swift-BAT triggers
  91. Swift-BAT Trigger 255685 is not a GRB
  92. Trigger 255685: Swift detection of a possible burst
  93. GRB 070110: VLT absorption redshift
  94. GRB 070110: UVOT Observations of a Candidate Afterglow
  95. GRB070110: Swift XRT Team refined analysis
  96. GRB 070110, Swift-BAT refined analysis
  97. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  98. GRB 070110: Swift detection of a burst with a possible optical afterglow
  99. IBAS Alert n. 4047: Not a GRB
  100. GRB070107: Swift/XRT refined analysis

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