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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"

45426 results found.

  1. GRB030323, ROTSE-III detection of possible optical counterpart
  2. GRB030323, optical observations
  3. GRB030324, BVRcIc field photometry
  4. GRB030323, possible optical counterpart
  5. GRB030323, BVRcIc field calibration
  6. GRB 030324 optical observations
  7. GRB 030320: Optical Observations
  8. GRB 030324, optical observations
  9. IPN triangulation of GRB030320B (annulus)
  10. IPN triangulation of GRB030320 (small error box)
  11. IPN triangulation of GRB030320
  12. Possible GRB 030320 localized by INTEGRAL
  13. GRB030226, addendum to GCN 1892
  14. IPN upper limit to a GRB associated with SN2003L
  15. IPN triangulation of GRB030317 (annulus)
  16. IPN triangulation of GRB030307 (annulus)
  17. GRB 030227: Optical limit at RIKEN
  18. GRB 030226 Optical observations
  19. IPN triangulation of GRB030306 (single small error box - REVISED)
  20. GRB030226: Optical observations at Asiago
  21. IPN triangulation of GRB030306 (single small error box)
  22. IPN triangulation of GRB030306 (two small error boxes)
  23. IPN triangulation of GRB030306 (intense; annulus only so far)
  24. GRB 030226: Optical observations
  25. GRB030226: Analysis of Chandra data
  26. IPN triangulation of GRB030304 (annulus)
  27. GRB 030227: Optical observations
  28. GRB030226, BVRc observations
  29. Chandra detection of the X-ray afterglow of GRB 030226
  30. GRB 030226, further optical/NIR imaging
  31. GRB030227, optical observations
  32. GRB 030226: Ic Observations
  33. GRB030227: Kiso optical upper limit
  34. IPN triangulation of GRB030301 (annulus)
  35. IPN triangulation of GRB030228 (annulus)
  36. GRB030227, BVRcIc field photometry
  37. GRB030226, BVRcIc field calibration
  38. 030302: NOT A GRB
  39. 030228: NOT A GRB
  40. GRB 030228, optical observations
  41. GRB 030226: Steep Decline
  42. GRB 030227: Confirmed Optical Afterglow (S1-A)
  43. GRB 030226: R band polarimetric observations
  44. GRB 030226: Optical observations
  45. GRB 030227: fading of candidate optical afterglow 'S1-A'
  46. GRB030227:Optical observations
  47. GRB 20030226: Upper limits from recent and historical observations
  48. GRB 030227, possible optical counterpart of XMM-Newton source
  49. GRB030227 - faint tentative OT candidate
  50. GRB 030226, optical observations
  51. XMM-Newton observation of GRB030227
  52. GRB030227: Kiso optical observations
  53. GRB 030227: Kyoto optical observation
  54. GRB 030226, optical light curve
  55. GRB 030226 spectroscopy
  56. GRB030227: refined INTEGRAL position
  57. GRB030227 localized by INTEGRAL
  58. Possible break in the GRB 030226 light curve
  59. GRB 030226 : Predicted light curve
  60. GRB030226: optical observation
  61. IPN triangulation of GRB030225 (annulus)
  62. GRB 030226: Confirmed decay index
  63. GRB030226: ESI spectroscopy
  64. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  65. GRB 030226 simultaneous optical observations
  66. Two absorption systems in GRB 030226
  67. GRB 030226, optical observations
  68. GRB030226: optical observations and refined redshift
  69. GRB030226: Optical decay index
  70. GRB 030226 Optical Spectra and R,I,z' Imaging
  71. GRB 030226, optical observations
  72. GRB 030226: Optical afterglow
  73. GRB030226: Candidate optical afterglow
  74. GRB 030217: Optical Observations at 4, 5, and 6 Days
  75. IPN triangulation of GRB030223 (annulus)
  76. IPN triangulation of GRB030220 (annulus)
  77. GRB: Non-Referencing of GCN Circulars.
  78. IPN triangulation of GRB030218 (annulus)
  79. GRB030217: optical observations
  80. IPN triangulation of GRB030217 (small error box)
  81. IPN triangulation of GRB030215C (annulus)
  82. IPN triangulation of GRB030217 (annulus)
  83. IPN triangulation of GRB030216 (annulus)
  84. IPN triangulation of GRB030215A and GRB030215B (annuli)
  85. GRB030115, WSRT radio observations - correction to GCN 1864
  86. GRB 030131: marginal optical detection
  87. GCN/INTEGRAL Mistake Fixed
  88. GRB030115, WSRT radio observations
  89. IPN triangulation of GRB030206 (annulus)
  90. IPN triangulation of GRB030208 (annulus)
  91. GRB 030204: Optical Observations
  92. GRB030204 field photometry
  93. GRB020819: Kiso R and I band observations
  94. GRB030131: Candidate Optical Afterglow
  95. GRB 030115: Optical Observations
  96. GRB 030204, optical observations
  97. IPN triangulation of GRB030204 (small error box)
  98. IPN triangulation of GRB030202 (annulus)
  99. GRB 030131, optical observations
  100. GRB030131: Kiso optical limit for corrected position

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