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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"

42584 results found.

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

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