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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"

32596 results found.

  1. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  2. GRB 030328: Optical observations
  3. Re: GRB 030328: Finding chart
  4. GRB 030328: Finding chart
  5. GRB 030328: Optical afterglow candidate
  6. GRB030131, BVRcIc field photometry
  7. Possible GRB030323 localized by INTEGRAL
  8. IPN triangulation of GRB030325 (final analysis)
  9. IPN triangulation of GRB030326 (single small error box)
  10. GRB 030323: SARA Optical Observations
  11. IPN triangulation of GRB030325 (single small error box)
  12. GRB030324, optical observations
  13. IPN triangulation of GRB030325 (two small error boxes)
  14. GRB 030324: TAROT optical observations
  15. GRB 030324 (HETE #2641): Optical observations
  16. GRB030324, Optical Observations
  17. GRB030323: Upper limits from recent and historical observations.
  18. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  19. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  20. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  21. VLT/FORS2 spectra of GRB 030323
  22. GRB030323, ROTSE-III detection of possible optical counterpart
  23. GRB030323, optical observations
  24. GRB030324, BVRcIc field photometry
  25. GRB030323, possible optical counterpart
  26. GRB030323, BVRcIc field calibration
  27. GRB 030324 optical observations
  28. GRB 030320: Optical Observations
  29. GRB 030324, optical observations
  30. IPN triangulation of GRB030320B (annulus)
  31. IPN triangulation of GRB030320 (small error box)
  32. IPN triangulation of GRB030320
  33. Possible GRB 030320 localized by INTEGRAL
  34. IPN upper limit to a GRB associated with SN2003L
  35. IPN triangulation of GRB030317 (annulus)
  36. IPN triangulation of GRB030307 (annulus)
  37. GRB 030227: Optical limit at RIKEN
  38. GRB 030226 Optical observations
  39. IPN triangulation of GRB030306 (single small error box - REVISED)
  40. GRB030226: Optical observations at Asiago
  41. IPN triangulation of GRB030306 (single small error box)
  42. IPN triangulation of GRB030306 (two small error boxes)
  43. IPN triangulation of GRB030306 (intense; annulus only so far)
  44. GRB 030226: Optical observations
  45. IPN triangulation of GRB030304 (annulus)
  46. GRB 030227: Optical observations
  47. GRB030226, BVRc observations
  48. Chandra detection of the X-ray afterglow of GRB 030226
  49. GRB 030226, further optical/NIR imaging
  50. GRB030227, optical observations
  51. GRB 030226: Ic Observations
  52. GRB030227: Kiso optical upper limit
  53. IPN triangulation of GRB030301 (annulus)
  54. IPN triangulation of GRB030228 (annulus)
  55. GRB030227, BVRcIc field photometry
  56. GRB030226, BVRcIc field calibration
  57. GRB 030227 optical afterglow
  58. 030302: NOT A GRB
  59. 030228: NOT A GRB
  60. GRB 030228, optical observations
  61. GRB 030226: Steep Decline
  62. GRB 030227: Confirmed Optical Afterglow (S1-A)
  63. GRB 030226: R band polarimetric observations
  64. GRB 030226: Optical observations
  65. GRB 030227: fading of candidate optical afterglow 'S1-A'
  66. GRB030227:Optical observations
  67. GRB 20030226: Upper limits from recent and historical observations
  68. GRB 030227, possible optical counterpart of XMM-Newton source
  69. GRB030227 - faint tentative OT candidate
  70. GRB 030226, optical observations
  71. GRB030227: Kiso optical observations
  72. GRB 030227: Kyoto optical observation
  73. GRB 030226, optical light curve
  74. GRB 030226 spectroscopy
  75. Possible break in the GRB 030226 light curve
  76. GRB 030226 : Predicted light curve
  77. IPN triangulation of GRB030225 (annulus)
  78. GRB 030226: Confirmed decay index
  79. GRB030226: ESI spectroscopy
  80. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  81. GRB 030226 simultaneous optical observations
  82. Two absorption systems in GRB 030226
  83. GRB 030226, optical observations
  84. GRB 030226 Optical Spectra and R,I,z' Imaging
  85. GRB 030226, optical observations
  86. GRB 030226: Optical afterglow
  87. GRB 030217: Optical Observations at 4, 5, and 6 Days
  88. IPN triangulation of GRB030223 (annulus)
  89. IPN triangulation of GRB030220 (annulus)
  90. GRB: Non-Referencing of GCN Circulars.
  91. IPN triangulation of GRB030218 (annulus)
  92. IPN triangulation of GRB030217 (small error box)
  93. IPN triangulation of GRB030215C (annulus)
  94. IPN triangulation of GRB030217 (annulus)
  95. IPN triangulation of GRB030216 (annulus)
  96. IPN triangulation of GRB030215A and GRB030215B (annuli)
  97. GRB030115, WSRT radio observations - correction to GCN 1864
  98. GRB 030131: marginal optical detection
  99. GRB030115, WSRT radio observations
  100. IPN triangulation of GRB030206 (annulus)

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