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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"

36076 results found.

  1. GRB 070227, Swift-BAT refined analysis
  2. GRB070227: possible X-ray afterglow detection
  3. GRB 070227: Swift detection of a burst in ground analysis
  4. GRB 920925C: optical afterglow candidate
  5. GRB 070224: Optical afterglow confirmation
  6. IBAS Alert n. 4144: not a GRB
  7. GRB 070224: Swift/UVOT Upper Limits
  8. VLA observation of GRB 070223
  9. VLA observation of GRB 070220
  10. GRB070224: Magellan Imaging Observations
  11. GRB 070224: WHT K-band imaging
  12. GRB 070224: MDM Observations
  13. GRB 070224: SARA upper limit
  14. GRB070224: Swift-XRT Refined Analysis
  15. GRB 070224: optical afterglow candidate
  16. GRB 070224, Swift-BAT refined analysis
  17. GRB 070224: MASTER-Net refind analysis
  18. GRB 070224: MASTER-VWF-Kislovodsk observations
  19. GRB 070224: MASTER observations
  20. GRB 070224: Swift detection of a burst
  21. GRB 070223: Optical observations
  22. GRB070223: Swift/UVOT refined analysis
  23. GRB 070223: Optical-IR observation with KANATA
  24. GRB 070223, Swift-BAT refined analysis
  25. GRB 070223: Swift-XRT Refined Analysis
  26. GRB 070220: pseudo-z~2.15 from spectral parameters of the prompt
  27. GRB070223 - SDSS Pre-Burst Observations
  28. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  29. GRB 070223: MDM Observations
  30. GRB070223: Swift burst
  31. Konus-Wind and Konus-A observations of GRB 070220
  32. GRB 070220: MITSuME Okayama Optical Observation
  33. GRB 070220: ART-3 Optical and NIR limits
  34. GRB 070220 Swift-BAT Refined Analysis
  35. Swift/UVOT refined analysis of GRB070220
  36. GRB 070209: Swift XRT refined analysis
  37. GRB 070220: Swift-XRT Refined Analysis
  38. GRB 070220: Observation with the KANATA 1.5m telescope
  39. GRB 070219: Gemini Observations
  40. GRB 070220 : Faulkes Telescope North optical limit
  41. GRB 070220: Swift detection of a burst
  42. GRB070219: MASTER-VWF-Kislovodsk observations
  43. GRB 070219: XRT Refined Analysis
  44. GRB 070219: Swift/UVOT Upper limits
  45. GRB 070219: I-band observations
  46. GRB 070219, Swift-BAT refined analysis
  47. GRB 070219: optical TNG observations
  48. GRB 070219: Liverpool Telescope Observations
  49. GRB 070219: ROTSE-III Optical Limits
  50. GRB070219 - SDSS Pre-Burst Observations
  51. GRB 070219: Swift detection of a burst
  52. IPN triangulation of GRB070201 (refined error box using MESSENGER data)
  53. GRB 070125 observations with the GMRT
  54. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  55. Swift-BAT trigger 260304 is NOT a burst or transient
  56. GRB 060927: PROMPT Observations
  57. GRB 070201: Correction to GCN 6094
  58. GRB 070129: MDM I-band Detection
  59. GRB 070125: Break in Optical Decay
  60. GRB 070209: Swift XRT analysis
  61. GRB 070201: clarification on localization and Konus-Wind spectra
  62. GRB070208: optical observations
  63. GRB 070201: IPN constraints and nearby galaxies
  64. GRB 070201: Proximity of IPN annulus to M31
  65. GRB 070208: MARGE Optical Observations
  66. IPN localization of very bright long hard GRB 070207
  67. IPN localization of very intense short GRB 070201
  68. GRB 070209, Swift-BAT refined analysis of the short hard burst
  69. GRB 070209: Swift detection of a short hard burst
  70. GRB 070208: Swift XRT refined analysis
  71. GRB 070208: RAPTOR detection of early afterglow onset
  72. GRB070208: Absorption and emission redshift from Gemini
  73. GRB 070208: MDM Optical Decay
  74. GRB 070208, Swift-BAT refined analysis
  75. GRB070208 - SDSS Pre-Burst Observations
  76. GRB 070208: Early IR detection and afterglow astrometry
  77. GRB 070208: Afterglow confirmation from P60
  78. GRB070208: Faulkes Telescope North Afterglow Identification
  79. GRB 070208: ROTSE-III Optical Limits
  80. GRB 070208: MDM Observations
  81. GRB 070208: Swift detection of a burst
  82. GRB 070125 detection with CARMA
  83. Swift-BAT trigger 259527 is a Cosmic Ray Shower
  84. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  85. GRB 070129: afterglow confirmation
  86. GRB070124: Swift-XRT Follow-up Observation
  87. GRB070126: Swift-XRT Observation
  88. GRB 070125: further AAVSO optical observations
  89. GRB 070129: Swift/UVOT Upper limits
  90. GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
  91. GRB 070125: optical observation
  92. GRB 070125: WSRT Radio Detection
  93. Radio detection of GRB 070125
  94. GRB061217: MAGIC telescope GeV observation
  95. GRB 070125: confirmation of pseudo-redshift
  96. GRB 070129, Swift-BAT refined analysis of a particularly long
  97. GRB 070129: Xinglong TNT optical Upper Limit
  98. GRB 070129: Swift-XRT Refined Analysis
  99. GRB 070129: VLT observations
  100. GRB 070125: An IR Point Source and an Apparent Host Galaxy

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