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

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