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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. VLA observation of GRB 070220
  2. GRB070224: Magellan Imaging Observations
  3. GRB 070224: WHT K-band imaging
  4. GRB 070224: MDM Observations
  5. GRB070224: Gemini Imaging Observations
  6. GRB 070224: SARA upper limit
  7. GRB070224: Swift-XRT Refined Analysis
  8. GRB 070224: optical afterglow candidate
  9. GRB 070224, Swift-BAT refined analysis
  10. GRB 070224: MASTER-Net refind analysis
  11. GRB 070224: MASTER-VWF-Kislovodsk observations
  12. GRB 070224: MASTER observations
  13. GRB 070224: Swift detection of a burst
  14. GRB 070223: Optical observations
  15. RHESSI Spectrum of GRB070220
  16. GRB070223: Swift/UVOT refined analysis
  17. GRB 070223: Optical-IR observation with KANATA
  18. GRB 070223, Swift-BAT refined analysis
  19. GRB070223: MASTER-VWF-Kislovodsk observations
  20. GRB 070223: Swift-XRT Refined Analysis
  21. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  22. GRB070223 - SDSS Pre-Burst Observations
  23. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  24. GRB 070223: MDM Observations
  25. GRB070223: Swift burst
  26. Konus-Wind and Konus-A observations of GRB 070220
  27. GRB 070220: MITSuME Okayama Optical Observation
  28. GRB 070220: ART-3 Optical and NIR limits
  29. GRB 070220 Swift-BAT Refined Analysis
  30. Swift/UVOT refined analysis of GRB070220
  31. GRB 070209: Swift XRT refined analysis
  32. GRB 070220: Swift-XRT Refined Analysis
  33. GRB 070220: Observation with the KANATA 1.5m telescope
  34. GRB 070219: Gemini Observations
  35. GRB 070220 : Faulkes Telescope North optical limit
  36. GRB 070220: Swift detection of a burst
  37. GRB070219: MASTER-VWF-Kislovodsk observations
  38. GRB 070219: XRT Refined Analysis
  39. GRB 070219: Swift/UVOT Upper limits
  40. GRB 070219: I-band observations
  41. GRB 070219, Swift-BAT refined analysis
  42. GRB 070219: optical TNG observations
  43. GRB 070219: Liverpool Telescope Observations
  44. GRB 070219: ROTSE-III Optical Limits
  45. GRB070219 - SDSS Pre-Burst Observations
  46. GRB 070219: Swift detection of a burst
  47. IPN triangulation of GRB070201 (refined error box using MESSENGER data)
  48. GRB 070125 observations with the GMRT
  49. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  50. Swift-BAT trigger 260304 is NOT a burst or transient
  51. GRB 060927: PROMPT Observations
  52. GRB 070201: Correction to GCN 6094
  53. GRB 070129: MDM I-band Detection
  54. GRB 070125: Break in Optical Decay
  55. GRB 070209: Swift XRT analysis
  56. GRB 070201: clarification on localization and Konus-Wind spectra
  57. GRB070208: optical observations
  58. GRB 070201: IPN constraints and nearby galaxies
  59. GRB 070201: Proximity of IPN annulus to M31
  60. GRB 070208: MARGE Optical Observations
  61. IPN localization of very bright long hard GRB 070207
  62. IPN localization of very intense short GRB 070201
  63. GRB 070209, Swift-BAT refined analysis of the short hard burst
  64. GRB 070209: Swift detection of a short hard burst
  65. GRB 070208: Swift XRT refined analysis
  66. GRB 070208: RAPTOR detection of early afterglow onset
  67. GRB070208: Absorption and emission redshift from Gemini
  68. GRB 070208: MDM Optical Decay
  69. GRB 070208, Swift-BAT refined analysis
  70. GRB070208 - SDSS Pre-Burst Observations
  71. GRB 070208: Early IR detection and afterglow astrometry
  72. GRB 070208: Afterglow confirmation from P60
  73. GRB070208: Faulkes Telescope North Afterglow Identification
  74. GRB 070208: ROTSE-III Optical Limits
  75. GRB 070208: MDM Observations
  76. GRB 070208: Swift detection of a burst
  77. GRB 070125 detection with CARMA
  78. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  79. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  80. GRB 070129: afterglow confirmation
  81. GRB070124: Swift-XRT Follow-up Observation
  82. GRB070126: Swift-XRT Observation
  83. GRB 070125: further AAVSO optical observations
  84. GRB 070129: Swift/UVOT Upper limits
  85. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  86. GRB 070125: optical observation
  87. GRB 070125: WSRT Radio Detection
  88. GRB070129: MITSuME optical observation
  89. Radio detection of GRB 070125
  90. GRB061217: MAGIC telescope GeV observation
  91. GRB 070125: confirmation of pseudo-redshift
  92. GRB 070129, Swift-BAT refined analysis of a particularly long
  93. GRB 070129: Xinglong TNT optical Upper Limit
  94. GRB 070129: Swift-XRT Refined Analysis
  95. GRB 070129: VLT observations
  96. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  97. GRB 070129: Swift detection of a burst
  98. GRB 070126: Swift/UVOT refined analysis
  99. GRB 070125: further AAVSO optical observations
  100. GRB 070125: MITSuME Okayama optical observation

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