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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"

23839 results found.

  1. XRF 030723: Detection of the likely host galaxy
  2. GRB030922 triangulation (annulus)
  3. GRB 030913: Optical limit at RIKEN
  4. XRF030824: optical observations
  5. GRB030823: optical observations
  6. GRB030823: optical observation at Tokyo Tech
  7. GRB 030817 = H2808 TAROT optical observations
  8. SGR 1808-20 (=H2802): A Possible new SGR
  9. XRF030723, ROTSE-III Early Observations
  10. XRF030723, optical observations
  11. GRBlog: Compilation of all GCN Circ. data
  12. HETE detection of burst from SGR1806-20
  13. MASTER: optical observation GRB030601
  14. GRB 030528: Optical observations at RIKEN
  15. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  16. GRB030429: RTT150 optical observations, a possible host galaxy
  17. GRB 030429: Radio Observations
  18. GRB 030429: redshift from VLT spectroscopy
  19. GRB030429: Optical Observations
  20. GRB 030501: TAROT possible candidate counterpart
  21. GRB 030429: confirmation of afterglow candidate
  22. GRB030429, possible optical counterpart
  23. GRB 030429: ROTSE-III observations
  24. GRB 030418: Optical afterglow candidate
  25. GRB030329: Near Infrared Observations at Gunma
  26. GRB030329: optical observations at Tokyo Tech
  27. Photometry of GRB030329 - Constant OT Magnitude
  28. GRB030329 - OT brightens
  29. GRB 030329: OT observations at Kanazawa
  30. 030331 NOT A GRB
  31. GRB030329 - Light curve flattening
  32. GRB030329 - near contemporaneous optical limits from CONCAM
  33. GRB 030329, optical observations
  34. GRB 030329: Upper limit from 5.6 hours before trigger
  35. GRB 030329: optical observations
  36. GRB 030329, R-band observations
  37. RXTE detection of GRB 030329 afterglow
  38. GRB 030329: Optical Afterglow Observations
  39. GRB 030328: Optical observations
  40. GRB 030328: optical observations
  41. GRB 030329: OT candidate
  42. VLT spectra of GRB 030328
  43. GRB030324 optical observation
  44. GRB030324, optical observations
  45. GRB030324, optical observations
  46. GRB 030324: TAROT optical observations
  47. GRB 030324 (HETE #2641): Optical observations
  48. GRB030324, Optical Observations
  49. VLT/FORS2 spectra of GRB 030323
  50. GRB030323, ROTSE-III detection of possible optical counterpart
  51. GRB030323, optical observations
  52. GRB030324, BVRcIc field photometry
  53. GRB030323, possible optical counterpart
  54. GRB030323, BVRcIc field calibration
  55. GRB 030324 optical observations
  56. GRB 030324, optical observations
  57. GRB 030227: Optical limit at RIKEN
  58. Chandra detection of the X-ray afterglow of GRB 030226
  59. 030302: NOT A GRB
  60. 030228: NOT A GRB
  61. GRB 030228, optical observations
  62. GRB 030226: R band polarimetric observations
  63. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  64. GRB 030226 simultaneous optical observations
  65. GRB030226: Candidate optical afterglow
  66. IPN triangulation of GRB030215C (annulus)
  67. GRB 030115, simultaneous observations by BOOTES-1
  68. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  69. Distribution of INTEGRAL SPI-ACS triggers
  70. GRB030115: TAROT optical observations
  71. GRB 030115, no optical candidate
  72. IPN triangulation of GRB030101 (two large error boxes)
  73. GRB021211: Measurement of Early Time Afterglow
  74. GRB021204: Kiso Observations
  75. GRB 021211, R- and I-band observations
  76. GRB021211, OT at 108 s
  77. HETE 2493: Optical observations
  78. HETE 2493: Optical candidate
  79. GRB 021204: Optical Observations at RIKEN
  80. GRB 021201: BOOTES simultaneous optical observations
  81. GRB 021112: RAPTOR Observations
  82. GRB021104: Optical Observations
  83. SGR1900+14 activity, November 2-4, 2002
  84. GRB021104: possible optical afterglow
  85. GRB 021016, optical observations
  86. GRB 021004: VRI observations at TNG: possible break
  87. GRB 021008, optical observations
  88. IPN triangulation of GRB021014 (large error box)
  89. GRB 021004: Additional V-band Polarimetric Observations
  90. GRB 021004: V-band Polarimetric Observations
  91. GRB 021004: Optical observations at RIKEN
  92. GRB 021004, SPM optical observations
  93. GRB021004: optical observations at Nyrola
  94. GRB021004: Optical Afterglow
  95. GRB 020903: Optical observations at RIKEN
  96. XRF 020903: Supernova
  97. IPN triangulation of GRB020914
  98. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  99. INTEGRAL GRBs added to GCN
  100. GRB020812: optical observation

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