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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"

45418 results found.

  1. IPN triangulation of GRB030320B (annulus)
  2. IPN triangulation of GRB030320 (small error box)
  3. IPN triangulation of GRB030320
  4. Possible GRB 030320 localized by INTEGRAL
  5. GRB030226, addendum to GCN 1892
  6. IPN upper limit to a GRB associated with SN2003L
  7. IPN triangulation of GRB030317 (annulus)
  8. IPN triangulation of GRB030307 (annulus)
  9. GRB 030227: Optical limit at RIKEN
  10. GRB 030226 Optical observations
  11. IPN triangulation of GRB030306 (single small error box - REVISED)
  12. GRB030226: Optical observations at Asiago
  13. IPN triangulation of GRB030306 (single small error box)
  14. IPN triangulation of GRB030306 (two small error boxes)
  15. IPN triangulation of GRB030306 (intense; annulus only so far)
  16. GRB 030226: Optical observations
  17. GRB030226: Analysis of Chandra data
  18. IPN triangulation of GRB030304 (annulus)
  19. GRB 030227: Optical observations
  20. GRB030226, BVRc observations
  21. Chandra detection of the X-ray afterglow of GRB 030226
  22. GRB 030226, further optical/NIR imaging
  23. GRB030227, optical observations
  24. GRB 030226: Ic Observations
  25. GRB030227: Kiso optical upper limit
  26. IPN triangulation of GRB030301 (annulus)
  27. IPN triangulation of GRB030228 (annulus)
  28. GRB030227, BVRcIc field photometry
  29. GRB030226, BVRcIc field calibration
  30. 030302: NOT A GRB
  31. 030228: NOT A GRB
  32. GRB 030228, optical observations
  33. GRB 030226: Steep Decline
  34. GRB 030227: Confirmed Optical Afterglow (S1-A)
  35. GRB 030226: R band polarimetric observations
  36. GRB 030226: Optical observations
  37. GRB 030227: fading of candidate optical afterglow 'S1-A'
  38. GRB030227:Optical observations
  39. GRB 20030226: Upper limits from recent and historical observations
  40. GRB 030227, possible optical counterpart of XMM-Newton source
  41. GRB030227 - faint tentative OT candidate
  42. GRB 030226, optical observations
  43. XMM-Newton observation of GRB030227
  44. GRB030227: Kiso optical observations
  45. GRB 030227: Kyoto optical observation
  46. GRB 030226, optical light curve
  47. GRB 030226 spectroscopy
  48. GRB030227: refined INTEGRAL position
  49. GRB030227 localized by INTEGRAL
  50. Possible break in the GRB 030226 light curve
  51. GRB 030226 : Predicted light curve
  52. GRB030226: optical observation
  53. IPN triangulation of GRB030225 (annulus)
  54. GRB 030226: Confirmed decay index
  55. GRB030226: ESI spectroscopy
  56. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  57. GRB 030226 simultaneous optical observations
  58. Two absorption systems in GRB 030226
  59. GRB 030226, optical observations
  60. GRB030226: optical observations and refined redshift
  61. GRB030226: Optical decay index
  62. GRB 030226 Optical Spectra and R,I,z' Imaging
  63. GRB 030226, optical observations
  64. GRB 030226: Optical afterglow
  65. GRB030226: Candidate optical afterglow
  66. GRB 030217: Optical Observations at 4, 5, and 6 Days
  67. IPN triangulation of GRB030223 (annulus)
  68. IPN triangulation of GRB030220 (annulus)
  69. GRB: Non-Referencing of GCN Circulars.
  70. IPN triangulation of GRB030218 (annulus)
  71. GRB030217: optical observations
  72. IPN triangulation of GRB030217 (small error box)
  73. IPN triangulation of GRB030215C (annulus)
  74. IPN triangulation of GRB030217 (annulus)
  75. IPN triangulation of GRB030216 (annulus)
  76. IPN triangulation of GRB030215A and GRB030215B (annuli)
  77. GRB030115, WSRT radio observations - correction to GCN 1864
  78. GRB 030131: marginal optical detection
  79. GCN/INTEGRAL Mistake Fixed
  80. GRB030115, WSRT radio observations
  81. IPN triangulation of GRB030206 (annulus)
  82. IPN triangulation of GRB030208 (annulus)
  83. GRB 030204: Optical Observations
  84. GRB030204 field photometry
  85. GRB020819: Kiso R and I band observations
  86. GRB030131: Candidate Optical Afterglow
  87. GRB 030115: Optical Observations
  88. GRB 030204, optical observations
  89. IPN triangulation of GRB030204 (small error box)
  90. IPN triangulation of GRB030202 (annulus)
  91. GRB 030131, optical observations
  92. GRB030131: Kiso optical limit for corrected position
  93. GRB030131: Optical limits for corrected position
  94. GRB 030131: afterglow candidate
  95. GRB 030115, late-time optical observations
  96. GRB030131: corrected INTEGRAL position
  97. Type Ic SN2003L (SN/GRB?), optical spectrum
  98. GRB030131: Kiso Observations
  99. GRB 020819: Host galaxy at Radio Position
  100. IPN triangulation of GRB030131 - CORRECTION

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