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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"

43583 results found.

  1. GRB 030329 follow-up
  2. GRB 030329: Optical afterglow candidate
  3. GRB 030329: OT candidate
  4. GRB 030329: Optical afterglow candidate
  5. GRB 030328: OT photometry
  6. GRB030328: optical spectroscopy at TNG
  7. GRB030328: optical photometry at the TNG
  8. VLT spectra of GRB 030328
  9. GRB 030328, optical spectroscopy
  10. GRB 030328, optical observations
  11. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  12. GRB 030328: Optical observations
  13. Re: GRB 030328: Finding chart
  14. GRB 030328: Finding chart
  15. GRB 030328: Optical afterglow candidate
  16. GRB030324 optical observation
  17. GRB030131, BVRcIc field photometry
  18. Possible GRB030323 localized by INTEGRAL
  19. IPN triangulation of GRB030325 (final analysis)
  20. GRB030323: Detection on 2003/03/24
  21. IPN triangulation of GRB030326 (single small error box)
  22. GRB 030323: SARA Optical Observations
  23. IPN triangulation of GRB030325 (single small error box)
  24. GRB030324, optical observations
  25. GRB030324, optical observations
  26. IPN triangulation of GRB030325 (two small error boxes)
  27. GRB 030324: TAROT optical observations
  28. GRB030323: V, R, I photometry
  29. GRB030324, Optical Observations
  30. GRB030323: Upper limits from recent and historical observations.
  31. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  32. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  33. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  34. VLT/FORS2 spectra of GRB 030323
  35. GRB030323, ROTSE-III detection of possible optical counterpart
  36. GRB030323, optical observations
  37. GRB030324, BVRcIc field photometry
  38. GRB030323, possible optical counterpart
  39. GRB030323, BVRcIc field calibration
  40. GRB 030324 optical observations
  41. GRB 030320: Optical Observations
  42. GRB 030324, optical observations
  43. IPN triangulation of GRB030320B (annulus)
  44. IPN triangulation of GRB030320 (small error box)
  45. IPN triangulation of GRB030320
  46. Possible GRB 030320 localized by INTEGRAL
  47. GRB030226, addendum to GCN 1892
  48. IPN upper limit to a GRB associated with SN2003L
  49. IPN triangulation of GRB030317 (annulus)
  50. IPN triangulation of GRB030307 (annulus)
  51. GRB 030227: Optical limit at RIKEN
  52. GRB 030226 Optical observations
  53. IPN triangulation of GRB030306 (single small error box - REVISED)
  54. GRB030226: Optical observations at Asiago
  55. IPN triangulation of GRB030306 (single small error box)
  56. IPN triangulation of GRB030306 (two small error boxes)
  57. IPN triangulation of GRB030306 (intense; annulus only so far)
  58. GRB 030226: Optical observations
  59. GRB030226: Analysis of Chandra data
  60. IPN triangulation of GRB030304 (annulus)
  61. GRB 030227: Optical observations
  62. GRB030226, BVRc observations
  63. Chandra detection of the X-ray afterglow of GRB 030226
  64. GRB 030226, further optical/NIR imaging
  65. GRB 030226: Ic Observations
  66. GRB030227: Kiso optical upper limit
  67. IPN triangulation of GRB030301 (annulus)
  68. IPN triangulation of GRB030228 (annulus)
  69. GRB030227, BVRcIc field photometry
  70. GRB030226, BVRcIc field calibration
  71. GRB 030227 optical afterglow
  72. 030302: NOT A GRB
  73. 030228: NOT A GRB
  74. GRB 030228, optical observations
  75. GRB 030226: Steep Decline
  76. GRB 030227: Confirmed Optical Afterglow (S1-A)
  77. GRB 030226: R band polarimetric observations
  78. GRB 030226: Optical observations
  79. GRB 030227: fading of candidate optical afterglow 'S1-A'
  80. GRB030227:Optical observations
  81. GRB 20030226: Upper limits from recent and historical observations
  82. GRB 030227, possible optical counterpart of XMM-Newton source
  83. GRB030227 - faint tentative OT candidate
  84. GRB 030226, optical observations
  85. XMM-Newton observation of GRB030227
  86. GRB030227: Kiso optical observations
  87. GRB 030227: Kyoto optical observation
  88. GRB 030226, optical light curve
  89. GRB 030226 spectroscopy
  90. Possible break in the GRB 030226 light curve
  91. GRB 030226 : Predicted light curve
  92. GRB030226: optical observation
  93. IPN triangulation of GRB030225 (annulus)
  94. GRB 030226: Confirmed decay index
  95. GRB030226: ESI spectroscopy
  96. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  97. GRB 030226 simultaneous optical observations
  98. GRB 030226, optical observations
  99. GRB030226: Optical decay index
  100. GRB 030226 Optical Spectra and R,I,z' Imaging

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