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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"

27027 results found.

  1. Activivty of SGR 1806-20
  2. GRB 040511: Optical limit
  3. GRB 040511: ROTSE-III Rapid Optical Upper Limits
  4. GRB040511: Optical Observations
  5. GRB040511: Optical Observations
  6. GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
  7. GRB040422: optical observations at CrAO
  8. GRB 040423 (=H3175): A Long GRB Localized by HETE
  9. GRB040422, optical observations at Loiano
  10. GRB 040422: ROTSE-IIIb Prompt Optical Limits
  11. GRB 040422,optical observation
  12. MASTER: HETE Alert 3163, 3167 technical optical observation
  13. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  14. IBAS GRB Alert 1694
  15. GRB 040228 Optical observations
  16. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  17. Follow-up on IBAS GRB Alert 1379
  18. IBAS GRB alert 1379
  19. GRB 031220: Optical observations of Chandra X-ray sources
  20. GRB040106: optical observations with REM+ROSS
  21. GRB031220: observation at Univercity of Miyazaki
  22. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  23. GRB031220(=H2976): Observation with the Chandra X-ray Observatory
  24. GRB 031220: Optical observation at Tokyo Tech
  25. GRB031220: ROTSE-IIIb Optical Limits
  26. IPN/HETE localization of GRB031203B (=H2949; large error box)
  27. IPN/HETE localization of GRB031109 (=H2917; large error box)
  28. GRB 031111, Radio observations
  29. HETE Prompt GRB Spectral Analyses
  30. GRB 031026: Ic Observations
  31. HETE Prompt GRB Light Curves and Color-Color Diagrams
  32. XRF 030723: Detection of the likely host galaxy
  33. GRB030922 triangulation (annulus)
  34. GRB 030913: Optical limit at RIKEN
  35. XRF030824: optical observations
  36. GRB030823: optical observations
  37. GRB030823: optical observation at Tokyo Tech
  38. GRB 030817 = H2808 TAROT optical observations
  39. SGR 1808-20 (=H2802): A Possible new SGR
  40. XRF030723, ROTSE-III Early Observations
  41. XRF030723, optical observations
  42. GRBlog: Compilation of all GCN Circ. data
  43. HETE detection of burst from SGR1806-20
  44. MASTER: optical observation GRB030601
  45. GRB 030528: Optical observations at RIKEN
  46. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  47. GRB030429: RTT150 optical observations, a possible host galaxy
  48. GRB 030429: Radio Observations
  49. GRB 030429: redshift from VLT spectroscopy
  50. GRB030429: Optical Observations
  51. GRB 030501: TAROT possible candidate counterpart
  52. GRB 030429: confirmation of afterglow candidate
  53. GRB030429, possible optical counterpart
  54. GRB 030429: ROTSE-III observations
  55. GRB 030418: Optical afterglow candidate
  56. GRB030329: Optical Observations
  57. GRB030329: Near Infrared Observations at Gunma
  58. GRB030329, optical observation
  59. GRB030329: optical observations at Tokyo Tech
  60. GRB030329: Optical observations
  61. GRB030329: Optical observations
  62. Photometry of GRB030329 - Constant OT Magnitude
  63. GRB030329 - OT brightens
  64. GRB 030329: OT observations at Kanazawa
  65. 030331 NOT A GRB
  66. GRB030329 - Light curve flattening
  67. GRB030329 - near contemporaneous optical limits from CONCAM
  68. GRB 030329, optical observations
  69. GRB030329: Optical observations
  70. GRB 030329: Upper limit from 5.6 hours before trigger
  71. GRB030329: Optical observations
  72. GRB 030329: optical observations
  73. GRB 030329, R-band observations
  74. RXTE detection of GRB 030329 afterglow
  75. GRB 030329: Optical Afterglow Observations
  76. GRB 030328: Optical observations
  77. GRB 030328: optical observations
  78. GRB 030329: OT candidate
  79. VLT spectra of GRB 030328
  80. GRB030324 optical observation
  81. GRB030324, optical observations
  82. GRB030324, optical observations
  83. GRB 030324: TAROT optical observations
  84. GRB 030324 (HETE #2641): Optical observations
  85. GRB030324, Optical Observations
  86. VLT/FORS2 spectra of GRB 030323
  87. GRB030323, ROTSE-III detection of possible optical counterpart
  88. GRB030323, optical observations
  89. GRB030324, BVRcIc field photometry
  90. GRB030323, possible optical counterpart
  91. GRB030323, BVRcIc field calibration
  92. GRB 030324 optical observations
  93. GRB 030324, optical observations
  94. GRB 030227: Optical limit at RIKEN
  95. Chandra detection of the X-ray afterglow of GRB 030226
  96. 030302: NOT A GRB
  97. 030228: NOT A GRB
  98. GRB 030228, optical observations
  99. GRB 030226: R band polarimetric observations
  100. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC

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