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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"

32697 results found.

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

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