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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"

45437 results found.

  1. GRB030324, optical observations
  2. IPN triangulation of GRB030325 (two small error boxes)
  3. GRB 030324: TAROT optical observations
  4. GRB030323: V, R, I photometry
  5. GRB 030324 (HETE #2641): Optical observations
  6. GRB030324, Optical Observations
  7. GRB030323: Upper limits from recent and historical observations.
  8. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  9. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  10. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  11. VLT/FORS2 spectra of GRB 030323
  12. GRB030323, ROTSE-III detection of possible optical counterpart
  13. GRB030323, optical observations
  14. GRB030324, BVRcIc field photometry
  15. GRB030323, possible optical counterpart
  16. GRB030323, BVRcIc field calibration
  17. GRB 030324 optical observations
  18. GRB 030320: Optical Observations
  19. GRB 030324, optical observations
  20. IPN triangulation of GRB030320B (annulus)
  21. IPN triangulation of GRB030320 (small error box)
  22. IPN triangulation of GRB030320
  23. Possible GRB 030320 localized by INTEGRAL
  24. GRB030226, addendum to GCN 1892
  25. IPN upper limit to a GRB associated with SN2003L
  26. IPN triangulation of GRB030317 (annulus)
  27. IPN triangulation of GRB030307 (annulus)
  28. GRB 030227: Optical limit at RIKEN
  29. GRB 030226 Optical observations
  30. IPN triangulation of GRB030306 (single small error box - REVISED)
  31. GRB030226: Optical observations at Asiago
  32. IPN triangulation of GRB030306 (single small error box)
  33. IPN triangulation of GRB030306 (two small error boxes)
  34. IPN triangulation of GRB030306 (intense; annulus only so far)
  35. GRB 030226: Optical observations
  36. GRB030226: Analysis of Chandra data
  37. IPN triangulation of GRB030304 (annulus)
  38. GRB 030227: Optical observations
  39. GRB030226, BVRc observations
  40. Chandra detection of the X-ray afterglow of GRB 030226
  41. GRB 030226, further optical/NIR imaging
  42. GRB030227, optical observations
  43. GRB 030226: Ic Observations
  44. GRB030227: Kiso optical upper limit
  45. IPN triangulation of GRB030301 (annulus)
  46. IPN triangulation of GRB030228 (annulus)
  47. GRB030227, BVRcIc field photometry
  48. GRB030226, BVRcIc field calibration
  49. 030302: NOT A GRB
  50. 030228: NOT A GRB
  51. GRB 030228, optical observations
  52. GRB 030226: Steep Decline
  53. GRB 030227: Confirmed Optical Afterglow (S1-A)
  54. GRB 030226: R band polarimetric observations
  55. GRB 030226: Optical observations
  56. GRB 030227: fading of candidate optical afterglow 'S1-A'
  57. GRB030227:Optical observations
  58. GRB 20030226: Upper limits from recent and historical observations
  59. GRB 030227, possible optical counterpart of XMM-Newton source
  60. GRB030227 - faint tentative OT candidate
  61. GRB 030226, optical observations
  62. XMM-Newton observation of GRB030227
  63. GRB030227: Kiso optical observations
  64. GRB 030227: Kyoto optical observation
  65. GRB 030226, optical light curve
  66. GRB 030226 spectroscopy
  67. GRB030227: refined INTEGRAL position
  68. GRB030227 localized by INTEGRAL
  69. Possible break in the GRB 030226 light curve
  70. GRB 030226 : Predicted light curve
  71. GRB030226: optical observation
  72. IPN triangulation of GRB030225 (annulus)
  73. GRB 030226: Confirmed decay index
  74. GRB030226: ESI spectroscopy
  75. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  76. GRB 030226 simultaneous optical observations
  77. Two absorption systems in GRB 030226
  78. GRB 030226, optical observations
  79. GRB030226: optical observations and refined redshift
  80. GRB030226: Optical decay index
  81. GRB 030226 Optical Spectra and R,I,z' Imaging
  82. GRB 030226, optical observations
  83. GRB 030226: Optical afterglow
  84. GRB030226: Candidate optical afterglow
  85. GRB 030217: Optical Observations at 4, 5, and 6 Days
  86. IPN triangulation of GRB030223 (annulus)
  87. IPN triangulation of GRB030220 (annulus)
  88. GRB: Non-Referencing of GCN Circulars.
  89. IPN triangulation of GRB030218 (annulus)
  90. GRB030217: optical observations
  91. IPN triangulation of GRB030217 (small error box)
  92. IPN triangulation of GRB030215C (annulus)
  93. IPN triangulation of GRB030217 (annulus)
  94. IPN triangulation of GRB030216 (annulus)
  95. IPN triangulation of GRB030215A and GRB030215B (annuli)
  96. GRB030115, WSRT radio observations - correction to GCN 1864
  97. GRB 030131: marginal optical detection
  98. GCN/INTEGRAL Mistake Fixed
  99. GRB030115, WSRT radio observations
  100. IPN triangulation of GRB030206 (annulus)

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