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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. GRB060219: optical observation
  2. GRB060206: optical observation
  3. GRB060218/SN2006aj: optical observations
  4. GRB 060218/SN 2006aj, LNA optical observation
  5. GRB060218: Refined photometric calibration of comparison stars
  6. GRB 060319: WHT K-band candidate afterglow
  7. GRB 060319: IAC-80 optical observations
  8. GRB060319: Swift XRT refined analysis
  9. GRB060319: Swift/UVOT upper limits
  10. GRB 060319: Re-analysis of TNG data
  11. GRB060319: MASTER limit
  12. GRB 060319: Swift-BAT refined analysis
  13. GRB 060319 optical observations at TNG
  14. GRB060319 : Liverpool Telescope optical limit
  15. GRB060319: MASTER optical observation
  16. GRB060319 - SDSS Pre-burst Observations
  17. GRB060319: Swift/XRT position
  18. GRB 060319: Swift detection of a burst
  19. GRB060313: Radio Observations
  20. GRB 060313: early afterglow NIR upper limits with REM
  21. IBAS Alert n. 3221: not a GRB
  22. Konus-Wind observation of GRB 060313
  23. GRB060313: SSO 40inch Observations
  24. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  25. GRB 060313: PROMPT Observations
  26. GRB 060313: Swift/UVOT Observations
  27. GRB060313:Gemini South Observations
  28. GRB 060313: Swift-XRT team refined analysis
  29. GRB060313: optical observations of the afterglow candidate
  30. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  31. GRB 060313, SMARTS optical counterpart?
  32. GRB 060313: Possible optical counterpart
  33. GRB 060313: Swift XRT position
  34. GRB 060313, SMARTS optical/IR observations
  35. GRB060313: optical and near infrared observations with REM
  36. GRB 060313: Swift-BAT detection of a bright short hard burst
  37. GRB060218: SARA Observations of SN2006aj
  38. GRB060312: Swift UVOT observation
  39. GRB 060312: Refined analysis of the Swift-BAT burst
  40. GRB 060218/SN 2006aj, high resolution spectra
  41. GRB 060312: Swift XRT team refined analysis
  42. GRB060306: APO Ks-band Imaging Observations
  43. GRB 060312: ROTSE-III Optical Limits
  44. GRB 060312: Swift detection of a burst
  45. IBAS Alert n. 3218 : not a real GRB
  46. GRB 060306: SOAR Ks Observations
  47. Bright short hard GRB 060303: IPN localization and Konus spectrum
  48. GRB060219: Liverpool Telescope observations
  49. GRB 060306: MAGNUM observations
  50. GRB060218: analysis of the XMM-Newton observation
  51. Swift/UVOT observations of GRB060306
  52. GRB 060306: Swift-BAT refined analysis
  53. GRB 060306: Swift-XRT team refined analysis
  54. GRB 060306: PROMPT Observations
  55. GRB 060306: Swift detection of a bright burst
  56. GRB 060218: RTT150 optical observations
  57. GRB060218: Ep,i - Eiso correlation
  58. GRB060218: R-band CCD photmetry
  59. GRB060223b: optical limit
  60. GRB060218/SN 2006aj: optical observation in V
  61. GRB060218/SN 2006aj: optical observation
  62. GRB 060121: HST observations
  63. GRB 060218 : GMRT observation [Correction and Improvement]
  64. GRB 060223b: Swift/UVOT Upper Limits
  65. GRB 060218/SN 2006aj: K-380 optical observations
  66. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  67. GRB200618: optical polarimetry and photometry
  68. GRB 060223B: Swift XRT possible afterglow
  69. GRB 060218/SN 2006aj: ABT observations
  70. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  71. GRB 060218 : Radio upper limits from GMRT
  72. GRB 060218/SN 2006aj: WIRO optical observations
  73. GRB 060218/SN 2006aj: RBO optical observations
  74. GRB 060204B: GETS early limit
  75. GRB 060218: Refined analysis of the radio afterglow
  76. GRB 060223A:Xinglong optical limits
  77. GRB 060223B: ART optical limits
  78. GRB 060223B: Swift-BAT refined analysis
  79. GRB 060223a: Swift/UVOT refined analysis
  80. GRB 060223: Swift XRT Team preliminary analysis
  81. GRB 060218/SN 2006aj: Swift-BAT fluence and peak flux
  82. GRB 060223B: Swift detection of a bright burst
  83. GRB 060223: Swift-BAT refined analysis
  84. GRB 060218: rebrightening
  85. Correction to GCN 4816 on GRB060218
  86. GRB 060218/SN 2006aj: optical observations
  87. GRB060218: Optical brightening in V and R
  88. GRB 060223: Keck redshift
  89. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  90. GRB 060223: Swift detection of a burst
  91. Spectral properties of GRB060218/SN2006aj
  92. GRB 060219: Swift-BAT refined analysis
  93. GRB 060218: rebrightening
  94. GRB 060218: emergence of the underlying SN spectrum
  95. GRB 060218: Decline in r-band flux
  96. GRB 060218: spectroscopic observations
  97. GRB 060218: Further refined analysis of the Swift-BAT burst
  98. GRB 060218: Likely an underluminous GRB
  99. GRB060218: Optical Spectroscopy of GRB-SN
  100. GRB060218: VLT spectroscopy

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