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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"

26173 results found.

  1. GRB 030418: Optical afterglow candidate
  2. GRB030329: Optical Observations
  3. GRB030329: Near Infrared Observations at Gunma
  4. GRB030329, optical observation
  5. GRB030329: optical observations at Tokyo Tech
  6. GRB030329: Optical observations
  7. GRB030329: Optical observations
  8. Photometry of GRB030329 - Constant OT Magnitude
  9. GRB030329 - OT brightens
  10. GRB 030329: OT observations at Kanazawa
  11. 030331 NOT A GRB
  12. GRB030329 - Light curve flattening
  13. GRB030329 - near contemporaneous optical limits from CONCAM
  14. GRB 030329, optical observations
  15. GRB030329: Optical observations
  16. GRB 030329: Upper limit from 5.6 hours before trigger
  17. GRB030329: Optical observations
  18. GRB 030329: optical observations
  19. GRB 030329, R-band observations
  20. RXTE detection of GRB 030329 afterglow
  21. GRB 030329: Optical Afterglow Observations
  22. GRB 030328: Optical observations
  23. GRB 030328: optical observations
  24. GRB 030329: OT candidate
  25. VLT spectra of GRB 030328
  26. GRB030324 optical observation
  27. GRB030324, optical observations
  28. GRB030324, optical observations
  29. GRB 030324: TAROT optical observations
  30. GRB 030324 (HETE #2641): Optical observations
  31. GRB030324, Optical Observations
  32. VLT/FORS2 spectra of GRB 030323
  33. GRB030323, ROTSE-III detection of possible optical counterpart
  34. GRB030323, optical observations
  35. GRB030324, BVRcIc field photometry
  36. GRB030323, possible optical counterpart
  37. GRB030323, BVRcIc field calibration
  38. GRB 030324 optical observations
  39. GRB 030324, optical observations
  40. GRB 030227: Optical limit at RIKEN
  41. Chandra detection of the X-ray afterglow of GRB 030226
  42. 030302: NOT A GRB
  43. 030228: NOT A GRB
  44. GRB 030228, optical observations
  45. GRB 030226: R band polarimetric observations
  46. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  47. GRB 030226 simultaneous optical observations
  48. GRB030226: Candidate optical afterglow
  49. IPN triangulation of GRB030215C (annulus)
  50. GRB 020819: afterglow candidate
  51. Publicizing GRB Discoveries - A Message from NASA HQ
  52. GRB 030115, simultaneous observations by BOOTES-1
  53. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  54. Distribution of INTEGRAL SPI-ACS triggers
  55. GRB030115: TAROT optical observations
  56. GRB 030115, no optical candidate
  57. IPN triangulation of GRB030101 (two large error boxes)
  58. GRB 021219: OSN optical observations
  59. GRB021211: Measurement of Early Time Afterglow
  60. GRB021204: Kiso Observations
  61. GRB 021201 (short/hard), NOT observations
  62. GRB 021211, R- and I-band observations
  63. GRB021211, OT at 108 s
  64. HETE 2493: Optical observations
  65. HETE 2493: Optical candidate
  66. GRB 021204: Optical Observations at RIKEN
  67. GRB 021201: BOOTES simultaneous optical observations
  68. GRB 021112: RAPTOR Observations
  69. GRB021104: Optical Observations
  70. SGR1900+14 activity, November 2-4, 2002
  71. GRB021104: possible optical afterglow
  72. GRB 021016, optical observations
  73. GRB 021004: VRI observations at TNG: possible break
  74. GRB 021008, optical observations
  75. IPN triangulation of GRB021014 (large error box)
  76. GRB 021004: Additional V-band Polarimetric Observations
  77. GRB 021004 - Unusual Radio-to-Submm Spectrum
  78. GRB 021004: V-band Polarimetric Observations
  79. IRAM Millimeter detection of GRB 021004
  80. GRB 021004: Optical observations at RIKEN
  81. GRB 021004, SPM optical observations
  82. GRB021004: optical observations at Nyrola
  83. GRB021004: Optical Afterglow
  84. GRB 020903: Optical observations at RIKEN
  85. XRF 020903: Supernova
  86. IPN triangulation of GRB020914
  87. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  88. INTEGRAL GRBs added to GCN
  89. GRB020812: optical observation
  90. Second epoch K band imaging of GRB 020819
  91. K band observation of GRB 020819
  92. HETE 2275: Optical observations
  93. Polarimetry of GRB020813: evidence for variability
  94. GRB020812: optical observations
  95. GRB020813: Early Time Magnitude
  96. GRB020813, optical observations
  97. Early Time Limits for GRB020813
  98. GRB 020813 Afterglow Observations; Possible break
  99. GRB 020813 multiband optical observations
  100. GRB020813: optical afterglow

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