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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 070220: Swift detection of a burst
  2. GRB070219: MASTER-VWF-Kislovodsk observations
  3. GRB 070219: XRT Refined Analysis
  4. GRB 070219: Swift/UVOT Upper limits
  5. GRB 070219: I-band observations
  6. GRB 070219, Swift-BAT refined analysis
  7. GRB 070219: optical TNG observations
  8. GRB 070219: Liverpool Telescope Observations
  9. GRB 070219: ROTSE-III Optical Limits
  10. GRB070219 - SDSS Pre-Burst Observations
  11. GRB 070219: Swift detection of a burst
  12. IPN triangulation of GRB070201 (refined error box using MESSENGER data)
  13. GRB 070125 observations with the GMRT
  14. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  15. Swift-BAT trigger 260304 is NOT a burst or transient
  16. GRB 060927: PROMPT Observations
  17. GRB 070201: Correction to GCN 6094
  18. GRB 070129: MDM I-band Detection
  19. GRB 070125: Break in Optical Decay
  20. GRB 070209: Swift XRT analysis
  21. GRB 070201: clarification on localization and Konus-Wind spectra
  22. GRB070208: optical observations
  23. GRB 070201: IPN constraints and nearby galaxies
  24. GRB 070201: Proximity of IPN annulus to M31
  25. GRB 070208: MARGE Optical Observations
  26. IPN localization of very bright long hard GRB 070207
  27. IPN localization of very intense short GRB 070201
  28. GRB 070209, Swift-BAT refined analysis of the short hard burst
  29. GRB 070209: Swift detection of a short hard burst
  30. GRB 070208: Swift XRT refined analysis
  31. GRB 070208: RAPTOR detection of early afterglow onset
  32. GRB070208: Absorption and emission redshift from Gemini
  33. GRB 070208: MDM Optical Decay
  34. GRB 070208, Swift-BAT refined analysis
  35. GRB070208 - SDSS Pre-Burst Observations
  36. GRB 070208: Early IR detection and afterglow astrometry
  37. GRB 070208: Afterglow confirmation from P60
  38. GRB070208: Faulkes Telescope North Afterglow Identification
  39. GRB 070208: ROTSE-III Optical Limits
  40. GRB 070208: MDM Observations
  41. GRB 070208: Swift detection of a burst
  42. GRB 070125 detection with CARMA
  43. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  44. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  45. GRB 070129: afterglow confirmation
  46. GRB070124: Swift-XRT Follow-up Observation
  47. GRB070126: Swift-XRT Observation
  48. GRB 070125: further AAVSO optical observations
  49. GRB 070129: Swift/UVOT Upper limits
  50. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  51. GRB 070125: optical observation
  52. GRB 070125: WSRT Radio Detection
  53. GRB070129: MITSuME optical observation
  54. Radio detection of GRB 070125
  55. GRB061217: MAGIC telescope GeV observation
  56. GRB 070125: confirmation of pseudo-redshift
  57. GRB 070129, Swift-BAT refined analysis of a particularly long
  58. GRB 070129: Xinglong TNT optical Upper Limit
  59. GRB 070129: Swift-XRT Refined Analysis
  60. GRB 070129: VLT observations
  61. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  62. GRB 070129: Swift detection of a burst
  63. GRB 070126: Swift/UVOT refined analysis
  64. GRB 070125: further AAVSO optical observations
  65. GRB 070125: MITSuME Okayama optical observation
  66. Konus-Wind observation of GRB 070125
  67. GRB 070125: AAVSO optical observations
  68. GRB 070125: optical observations
  69. GRB 070126: VLT observations
  70. GRB070126: Swift-XRT possible detection of an afterglow
  71. GRB 070125: PROMPT detections
  72. GRB 070124: Suzaku WAM observation of the prompt emissions
  73. GRB 070125: WSRT Radio Observations
  74. GRB 070125: UVOT Detection in Ultraviolet Filters
  75. GRB 070126, Swift-BAT refined analysis of a very faint burst
  76. GRB070125: Optical observation by Kanata
  77. GRB070124: Swift-XRT Observation
  78. Possible GRB 070126: Swift/UVOT Upper Limit
  79. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  80. GRB 070125: Xinglong TNT optical observations
  81. GRB 070125: Continued P60 Observations
  82. GRB 070125: pseudo-z~1.5 from spectral parameters of the prompt emission
  83. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  84. GRB 070125: Lick 3m Spectroscopy
  85. GRB070125: Swift-XRT Refined Analysis
  86. GRB 070125: SARA detection in R
  87. GRB 070125: P60 Optical Afterglow Candidate
  88. GRB 070126?: Swift detection of a possible burst
  89. GRB070125 redshift request
  90. RHESSI Spectrum of GRB070125
  91. IPN-BAT localization of GRB070125 (very long duration, intense)
  92. Konus-Wind observation of short hard GRB 070124
  93. IPN localization of GRB070124 (short duration, hard spectrum)
  94. GRB 070110: optical break
  95. Swift-BAT trigger 257213 is a Galactic Center transient
  96. GRB 070110: Continued Detection and Request for Ground Followup
  97. GRB 050904: Second Epoch of HST/NICMOS Observations
  98. GRB 070110: Ep,i - Eiso correlation
  99. GRB 070107: Suzaku WAM observation of the prompt emission
  100. GRB 070110: VLT R-band photometry

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