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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"

38366 results found.

  1. GRB030324 optical observation
  2. GRB030131, BVRcIc field photometry
  3. Possible GRB030323 localized by INTEGRAL
  4. IPN triangulation of GRB030325 (final analysis)
  5. GRB030323: Detection on 2003/03/24
  6. IPN triangulation of GRB030326 (single small error box)
  7. GRB 030323: SARA Optical Observations
  8. IPN triangulation of GRB030325 (single small error box)
  9. IPN triangulation of GRB030325 (two small error boxes)
  10. GRB030323: V, R, I photometry
  11. GRB030324, Optical Observations
  12. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  13. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  14. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  15. GRB030323, ROTSE-III detection of possible optical counterpart
  16. GRB030324, BVRcIc field photometry
  17. GRB030323, possible optical counterpart
  18. GRB030323, BVRcIc field calibration
  19. IPN triangulation of GRB030320B (annulus)
  20. IPN triangulation of GRB030320 (small error box)
  21. IPN triangulation of GRB030320
  22. Possible GRB 030320 localized by INTEGRAL
  23. IPN upper limit to a GRB associated with SN2003L
  24. IPN triangulation of GRB030317 (annulus)
  25. IPN triangulation of GRB030307 (annulus)
  26. GRB 030226 Optical observations
  27. IPN triangulation of GRB030306 (single small error box - REVISED)
  28. GRB030226: Optical observations at Asiago
  29. IPN triangulation of GRB030306 (single small error box)
  30. IPN triangulation of GRB030306 (two small error boxes)
  31. IPN triangulation of GRB030306 (intense; annulus only so far)
  32. GRB030226: Analysis of Chandra data
  33. IPN triangulation of GRB030304 (annulus)
  34. Chandra detection of the X-ray afterglow of GRB 030226
  35. GRB 030226, further optical/NIR imaging
  36. GRB 030226: Ic Observations
  37. GRB030227: Kiso optical upper limit
  38. IPN triangulation of GRB030301 (annulus)
  39. IPN triangulation of GRB030228 (annulus)
  40. GRB030227, BVRcIc field photometry
  41. GRB030226, BVRcIc field calibration
  42. GRB 030227 optical afterglow
  43. 030302: NOT A GRB
  44. 030228: NOT A GRB
  45. GRB 030228, optical observations
  46. GRB 030226: Steep Decline
  47. GRB 030227: Confirmed Optical Afterglow (S1-A)
  48. GRB 030226: R band polarimetric observations
  49. GRB 030227: fading of candidate optical afterglow 'S1-A'
  50. GRB030227:Optical observations
  51. GRB 20030226: Upper limits from recent and historical observations
  52. GRB 030227, possible optical counterpart of XMM-Newton source
  53. GRB030227 - faint tentative OT candidate
  54. GRB 030226, optical observations
  55. XMM-Newton observation of GRB030227
  56. GRB030227: Kiso optical observations
  57. GRB 030227: Kyoto optical observation
  58. GRB 030226, optical light curve
  59. GRB 030226 spectroscopy
  60. GRB030227 localized by INTEGRAL
  61. Possible break in the GRB 030226 light curve
  62. GRB 030226 : Predicted light curve
  63. GRB030226: optical observation
  64. IPN triangulation of GRB030225 (annulus)
  65. GRB030226: ESI spectroscopy
  66. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  67. GRB 030226 simultaneous optical observations
  68. Two absorption systems in GRB 030226
  69. GRB 030226, optical observations
  70. GRB 030226 Optical Spectra and R,I,z' Imaging
  71. GRB 030226, optical observations
  72. GRB 030217: Optical Observations at 4, 5, and 6 Days
  73. IPN triangulation of GRB030223 (annulus)
  74. IPN triangulation of GRB030220 (annulus)
  75. GRB: Non-Referencing of GCN Circulars.
  76. IPN triangulation of GRB030218 (annulus)
  77. GRB030217: optical observations
  78. IPN triangulation of GRB030217 (small error box)
  79. IPN triangulation of GRB030215C (annulus)
  80. IPN triangulation of GRB030217 (annulus)
  81. IPN triangulation of GRB030216 (annulus)
  82. IPN triangulation of GRB030215A and GRB030215B (annuli)
  83. GRB030115, WSRT radio observations - correction to GCN 1864
  84. GRB 030131: marginal optical detection
  85. GCN/INTEGRAL Mistake Fixed
  86. GRB030115, WSRT radio observations
  87. IPN triangulation of GRB030206 (annulus)
  88. IPN triangulation of GRB030208 (annulus)
  89. GRB 030204: Optical Observations
  90. GRB030204 field photometry
  91. GRB020819: Kiso R and I band observations
  92. GRB030131: Candidate Optical Afterglow
  93. GRB 030115: Optical Observations
  94. GRB 030204, optical observations
  95. IPN triangulation of GRB030204 (small error box)
  96. IPN triangulation of GRB030202 (annulus)
  97. GRB 030131, optical observations
  98. GRB030131: Kiso optical limit for corrected position
  99. GRB030131: Optical limits for corrected position
  100. GRB 030131: afterglow candidate

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