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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. RHESSI Spectrum of GRB070220
  2. GRB070223: Swift/UVOT refined analysis
  3. GRB 070223: Optical-IR observation with KANATA
  4. GRB 070223, Swift-BAT refined analysis
  5. GRB070223: MASTER-VWF-Kislovodsk observations
  6. GRB 070223: Swift-XRT Refined Analysis
  7. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  8. GRB070223 - SDSS Pre-Burst Observations
  9. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  10. GRB 070223: MDM Observations
  11. GRB070223: Swift burst
  12. Konus-Wind and Konus-A observations of GRB 070220
  13. GRB 070220: MITSuME Okayama Optical Observation
  14. GRB 070220: ART-3 Optical and NIR limits
  15. GRB 070220 Swift-BAT Refined Analysis
  16. Swift/UVOT refined analysis of GRB070220
  17. GRB 070209: Swift XRT refined analysis
  18. GRB 070220: Swift-XRT Refined Analysis
  19. GRB 070220: Observation with the KANATA 1.5m telescope
  20. GRB 070219: Gemini Observations
  21. GRB 070220 : Faulkes Telescope North optical limit
  22. GRB 070220: Swift detection of a burst
  23. GRB070219: MASTER-VWF-Kislovodsk observations
  24. GRB 070219: XRT Refined Analysis
  25. GRB 070219: Swift/UVOT Upper limits
  26. GRB 070219: I-band observations
  27. GRB 070219, Swift-BAT refined analysis
  28. GRB 070219: optical TNG observations
  29. GRB 070219: Liverpool Telescope Observations
  30. GRB 070219: ROTSE-III Optical Limits
  31. GRB070219 - SDSS Pre-Burst Observations
  32. GRB 070219: Swift detection of a burst
  33. IPN triangulation of GRB070201 (refined error box using MESSENGER data)
  34. GRB 070125 observations with the GMRT
  35. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  36. Swift-BAT trigger 260304 is NOT a burst or transient
  37. GRB 060927: PROMPT Observations
  38. GRB 070201: Correction to GCN 6094
  39. GRB 070129: MDM I-band Detection
  40. GRB 070125: Break in Optical Decay
  41. GRB 070209: Swift XRT analysis
  42. GRB 070201: clarification on localization and Konus-Wind spectra
  43. GRB070208: optical observations
  44. GRB 070201: IPN constraints and nearby galaxies
  45. GRB 070201: Proximity of IPN annulus to M31
  46. GRB 070208: MARGE Optical Observations
  47. IPN localization of very bright long hard GRB 070207
  48. IPN localization of very intense short GRB 070201
  49. GRB 070209, Swift-BAT refined analysis of the short hard burst
  50. GRB 070209: Swift detection of a short hard burst
  51. GRB 070208: Swift XRT refined analysis
  52. GRB 070208: RAPTOR detection of early afterglow onset
  53. GRB070208: Absorption and emission redshift from Gemini
  54. GRB 070208: MDM Optical Decay
  55. GRB 070208, Swift-BAT refined analysis
  56. GRB070208 - SDSS Pre-Burst Observations
  57. GRB 070208: Early IR detection and afterglow astrometry
  58. GRB 070208: Afterglow confirmation from P60
  59. GRB070208: Faulkes Telescope North Afterglow Identification
  60. GRB 070208: ROTSE-III Optical Limits
  61. GRB 070208: MDM Observations
  62. GRB 070208: Swift detection of a burst
  63. GRB 070125 detection with CARMA
  64. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  65. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  66. GRB 070129: afterglow confirmation
  67. GRB070124: Swift-XRT Follow-up Observation
  68. GRB070126: Swift-XRT Observation
  69. GRB 070125: further AAVSO optical observations
  70. GRB 070129: Swift/UVOT Upper limits
  71. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  72. GRB 070125: optical observation
  73. GRB 070125: WSRT Radio Detection
  74. GRB070129: MITSuME optical observation
  75. Radio detection of GRB 070125
  76. GRB061217: MAGIC telescope GeV observation
  77. GRB 070125: confirmation of pseudo-redshift
  78. GRB 070129, Swift-BAT refined analysis of a particularly long
  79. GRB 070129: Xinglong TNT optical Upper Limit
  80. GRB 070129: Swift-XRT Refined Analysis
  81. GRB 070129: VLT observations
  82. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  83. GRB 070129: Swift detection of a burst
  84. GRB 070126: Swift/UVOT refined analysis
  85. GRB 070125: further AAVSO optical observations
  86. GRB 070125: MITSuME Okayama optical observation
  87. Konus-Wind observation of GRB 070125
  88. GRB 070125: AAVSO optical observations
  89. GRB 070125: optical observations
  90. GRB 070126: VLT observations
  91. GRB070126: Swift-XRT possible detection of an afterglow
  92. GRB 070125: PROMPT detections
  93. GRB 070124: Suzaku WAM observation of the prompt emissions
  94. GRB 070125: WSRT Radio Observations
  95. GRB 070125: UVOT Detection in Ultraviolet Filters
  96. GRB 070126, Swift-BAT refined analysis of a very faint burst
  97. GRB070125: Optical observation by Kanata
  98. GRB070124: Swift-XRT Observation
  99. Possible GRB 070126: Swift/UVOT Upper Limit
  100. GRB 070125: UVOT Observations of a Fading Optical Afterglow

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