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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"

45518 results found.

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

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