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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"

36043 results found.

  1. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  2. GRB 060323: Swift/XRT position
  3. GRB 060322: Refined analysis of the Swift-BAT burst
  4. GRB060323 - SDSS Pre-Burst Observations
  5. GRB 060323: Swift detection of a burst with a possible optical afterglow
  6. GRB 060322: Swift-BAT detection of a 200-sec burst
  7. GRB060219: optical observation
  8. GRB060206: optical observation
  9. GRB060218/SN2006aj: optical observations
  10. GRB 060218/SN 2006aj, LNA optical observation
  11. GRB060218: Refined photometric calibration of comparison stars
  12. GRB 060319: WHT K-band candidate afterglow
  13. GRB 060319: IAC-80 optical observations
  14. GRB060319: Swift XRT refined analysis
  15. GRB 060319: Re-analysis of TNG data
  16. GRB060319: MASTER limit
  17. GRB 060319: Swift-BAT refined analysis
  18. GRB 060319 optical observations at TNG
  19. GRB060319 : Liverpool Telescope optical limit
  20. GRB060319: MASTER optical observation
  21. GRB060319 - SDSS Pre-burst Observations
  22. GRB 060319: Swift detection of a burst
  23. GRB060313: Radio Observations
  24. GRB 060313: early afterglow NIR upper limits with REM
  25. IBAS Alert n. 3221: not a GRB
  26. Konus-Wind observation of GRB 060313
  27. GRB060313: SSO 40inch Observations
  28. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  29. GRB 060313: PROMPT Observations
  30. GRB 060313: Swift/UVOT Observations
  31. GRB060313:Gemini South Observations
  32. GRB 060313: Swift-XRT team refined analysis
  33. GRB060313: optical observations of the afterglow candidate
  34. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  35. GRB 060313, SMARTS optical counterpart?
  36. GRB 060313: Possible optical counterpart
  37. GRB 060313: Swift XRT position
  38. GRB 060313, SMARTS optical/IR observations
  39. GRB060313: optical and near infrared observations with REM
  40. GRB 060313: Swift-BAT detection of a bright short hard burst
  41. GRB060218: SARA Observations of SN2006aj
  42. GRB 060312: Refined analysis of the Swift-BAT burst
  43. GRB 060218/SN 2006aj, high resolution spectra
  44. GRB 060312: Swift XRT team refined analysis
  45. GRB060306: APO Ks-band Imaging Observations
  46. GRB 060312: ROTSE-III Optical Limits
  47. GRB 060312: Swift detection of a burst
  48. IBAS Alert n. 3218 : not a real GRB
  49. GRB 060306: SOAR Ks Observations
  50. Bright short hard GRB 060303: IPN localization and Konus spectrum
  51. GRB 060306: MAGNUM observations
  52. GRB060218: analysis of the XMM-Newton observation
  53. Swift/UVOT observations of GRB060306
  54. GRB 060306: Swift-BAT refined analysis
  55. GRB 060306: Swift-XRT team refined analysis
  56. GRB 060306: PROMPT Observations
  57. GRB 060306: Swift detection of a bright burst
  58. GRB 060218: RTT150 optical observations
  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. GRB 060223B: Swift XRT possible afterglow
  68. GRB 060218/SN 2006aj: ABT observations
  69. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  70. GRB 060218 : Radio upper limits from GMRT
  71. GRB 060218/SN 2006aj: WIRO optical observations
  72. GRB 060218/SN 2006aj: RBO optical observations
  73. GRB 060204B: GETS early limit
  74. GRB 060218: Refined analysis of the radio afterglow
  75. GRB 060223A:Xinglong optical limits
  76. GRB 060223B: ART optical limits
  77. GRB 060223B: Swift-BAT refined analysis
  78. GRB 060223a: Swift/UVOT refined analysis
  79. GRB 060223: Swift XRT Team preliminary analysis
  80. GRB 060218/SN 2006aj: Swift-BAT fluence and peak flux
  81. GRB 060223B: Swift detection of a bright burst
  82. GRB 060223: Swift-BAT refined analysis
  83. GRB 060218: rebrightening
  84. GRB 060218/SN 2006aj: optical observations
  85. GRB 060223: Keck redshift
  86. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  87. GRB 060223: Swift detection of a burst
  88. Spectral properties of GRB060218/SN2006aj
  89. GRB 060219: Swift-BAT refined analysis
  90. GRB 060218: rebrightening
  91. GRB 060218: emergence of the underlying SN spectrum
  92. GRB 060218: Decline in r-band flux
  93. GRB 060218: spectroscopic observations
  94. GRB 060218: Further refined analysis of the Swift-BAT burst
  95. GRB 060218: Likely an underluminous GRB
  96. GRB060218: Optical Spectroscopy of GRB-SN
  97. GRB060218: VLT spectroscopy
  98. GRB 060218: Optical Observations at Xinglong Obs.
  99. GRB 060219: SDSS galaxy inside XRT error circle
  100. GRB060218: UV Detection and Light Curves

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