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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"

27015 results found.

  1. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  2. IBAS GRB Alert 1694
  3. GRB 040228 Optical observations
  4. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  5. Follow-up on IBAS GRB Alert 1379
  6. IBAS GRB alert 1379
  7. GRB 031220: Optical observations of Chandra X-ray sources
  8. GRB040106: optical observations with REM+ROSS
  9. GRB031220: observation at Univercity of Miyazaki
  10. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  11. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  12. GRB 031220: Optical observation at Tokyo Tech
  13. GRB031220: ROTSE-IIIb Optical Limits
  14. IPN/HETE localization of GRB031203B (=H2949; large error box)
  15. IPN/HETE localization of GRB031109 (=H2917; large error box)
  16. GRB 031111, Radio observations
  17. HETE Prompt GRB Spectral Analyses
  18. GRB 031026: Ic Observations
  19. HETE Prompt GRB Light Curves and Color-Color Diagrams
  20. XRF 030723: Detection of the likely host galaxy
  21. GRB030922 triangulation (annulus)
  22. GRB 030913: Optical limit at RIKEN
  23. XRF030824: optical observations
  24. GRB030823: optical observations
  25. GRB030823: optical observation at Tokyo Tech
  26. GRB 030817 = H2808 TAROT optical observations
  27. SGR 1808-20 (=H2802): A Possible new SGR
  28. XRF030723, ROTSE-III Early Observations
  29. XRF030723, optical observations
  30. GRBlog: Compilation of all GCN Circ. data
  31. HETE detection of burst from SGR1806-20
  32. MASTER: optical observation GRB030601
  33. GRB 030528: Optical observations at RIKEN
  34. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  35. GRB030429: RTT150 optical observations, a possible host galaxy
  36. GRB 030429: Radio Observations
  37. GRB 030429: redshift from VLT spectroscopy
  38. GRB030429: Optical Observations
  39. GRB 030501: TAROT possible candidate counterpart
  40. GRB 030429: confirmation of afterglow candidate
  41. GRB030429, possible optical counterpart
  42. GRB 030429: ROTSE-III observations
  43. GRB 030418: Optical afterglow candidate
  44. GRB030329: Optical Observations
  45. GRB030329: Near Infrared Observations at Gunma
  46. GRB030329, optical observation
  47. GRB030329: optical observations at Tokyo Tech
  48. GRB030329: Optical observations
  49. GRB030329: Optical observations
  50. Photometry of GRB030329 - Constant OT Magnitude
  51. GRB030329 - OT brightens
  52. GRB 030329: OT observations at Kanazawa
  53. 030331 NOT A GRB
  54. GRB030329 - Light curve flattening
  55. GRB030329 - near contemporaneous optical limits from CONCAM
  56. GRB 030329, optical observations
  57. GRB030329: Optical observations
  58. GRB 030329: Upper limit from 5.6 hours before trigger
  59. GRB030329: Optical observations
  60. GRB 030329: optical observations
  61. GRB 030329, R-band observations
  62. RXTE detection of GRB 030329 afterglow
  63. GRB 030329: Optical Afterglow Observations
  64. GRB 030328: Optical observations
  65. GRB 030328: optical observations
  66. GRB 030329: OT candidate
  67. VLT spectra of GRB 030328
  68. GRB030324 optical observation
  69. GRB030324, optical observations
  70. GRB030324, optical observations
  71. GRB 030324: TAROT optical observations
  72. GRB 030324 (HETE #2641): Optical observations
  73. GRB030324, Optical Observations
  74. VLT/FORS2 spectra of GRB 030323
  75. GRB030323, ROTSE-III detection of possible optical counterpart
  76. GRB030323, optical observations
  77. GRB030324, BVRcIc field photometry
  78. GRB030323, possible optical counterpart
  79. GRB030323, BVRcIc field calibration
  80. GRB 030324 optical observations
  81. GRB 030324, optical observations
  82. GRB 030227: Optical limit at RIKEN
  83. Chandra detection of the X-ray afterglow of GRB 030226
  84. 030302: NOT A GRB
  85. 030228: NOT A GRB
  86. GRB 030228, optical observations
  87. GRB 030226: R band polarimetric observations
  88. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  89. GRB 030226 simultaneous optical observations
  90. GRB030226: Candidate optical afterglow
  91. IPN triangulation of GRB030215C (annulus)
  92. GRB 020819: afterglow candidate
  93. Publicizing GRB Discoveries - A Message from NASA HQ
  94. GRB 030115, simultaneous observations by BOOTES-1
  95. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  96. Distribution of INTEGRAL SPI-ACS triggers
  97. GRB030115: TAROT optical observations
  98. GRB 030115, no optical candidate
  99. IPN triangulation of GRB030101 (two large error boxes)
  100. GRB 021219: OSN optical observations

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