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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"

38357 results found.

  1. GRB030323: V, R, I photometry
  2. GRB030324, Optical Observations
  3. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  4. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  5. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  6. GRB030323, ROTSE-III detection of possible optical counterpart
  7. GRB030324, BVRcIc field photometry
  8. GRB030323, possible optical counterpart
  9. GRB030323, BVRcIc field calibration
  10. IPN triangulation of GRB030320B (annulus)
  11. IPN triangulation of GRB030320 (small error box)
  12. IPN triangulation of GRB030320
  13. Possible GRB 030320 localized by INTEGRAL
  14. IPN upper limit to a GRB associated with SN2003L
  15. IPN triangulation of GRB030317 (annulus)
  16. IPN triangulation of GRB030307 (annulus)
  17. GRB 030226 Optical observations
  18. IPN triangulation of GRB030306 (single small error box - REVISED)
  19. GRB030226: Optical observations at Asiago
  20. IPN triangulation of GRB030306 (single small error box)
  21. IPN triangulation of GRB030306 (two small error boxes)
  22. IPN triangulation of GRB030306 (intense; annulus only so far)
  23. GRB030226: Analysis of Chandra data
  24. IPN triangulation of GRB030304 (annulus)
  25. Chandra detection of the X-ray afterglow of GRB 030226
  26. GRB 030226, further optical/NIR imaging
  27. GRB 030226: Ic Observations
  28. GRB030227: Kiso optical upper limit
  29. IPN triangulation of GRB030301 (annulus)
  30. IPN triangulation of GRB030228 (annulus)
  31. GRB030227, BVRcIc field photometry
  32. GRB030226, BVRcIc field calibration
  33. GRB 030227 optical afterglow
  34. 030302: NOT A GRB
  35. 030228: NOT A GRB
  36. GRB 030228, optical observations
  37. GRB 030226: Steep Decline
  38. GRB 030227: Confirmed Optical Afterglow (S1-A)
  39. GRB 030226: R band polarimetric observations
  40. GRB 030227: fading of candidate optical afterglow 'S1-A'
  41. GRB030227:Optical observations
  42. GRB 20030226: Upper limits from recent and historical observations
  43. GRB 030227, possible optical counterpart of XMM-Newton source
  44. GRB030227 - faint tentative OT candidate
  45. GRB 030226, optical observations
  46. XMM-Newton observation of GRB030227
  47. GRB030227: Kiso optical observations
  48. GRB 030227: Kyoto optical observation
  49. GRB 030226, optical light curve
  50. GRB 030226 spectroscopy
  51. GRB030227 localized by INTEGRAL
  52. Possible break in the GRB 030226 light curve
  53. GRB 030226 : Predicted light curve
  54. GRB030226: optical observation
  55. IPN triangulation of GRB030225 (annulus)
  56. GRB030226: ESI spectroscopy
  57. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  58. GRB 030226 simultaneous optical observations
  59. Two absorption systems in GRB 030226
  60. GRB 030226, optical observations
  61. GRB 030226 Optical Spectra and R,I,z' Imaging
  62. GRB 030226, optical observations
  63. GRB 030217: Optical Observations at 4, 5, and 6 Days
  64. IPN triangulation of GRB030223 (annulus)
  65. IPN triangulation of GRB030220 (annulus)
  66. GRB: Non-Referencing of GCN Circulars.
  67. IPN triangulation of GRB030218 (annulus)
  68. GRB030217: optical observations
  69. IPN triangulation of GRB030217 (small error box)
  70. IPN triangulation of GRB030215C (annulus)
  71. IPN triangulation of GRB030217 (annulus)
  72. IPN triangulation of GRB030216 (annulus)
  73. IPN triangulation of GRB030215A and GRB030215B (annuli)
  74. GRB030115, WSRT radio observations - correction to GCN 1864
  75. GRB 030131: marginal optical detection
  76. GCN/INTEGRAL Mistake Fixed
  77. GRB030115, WSRT radio observations
  78. IPN triangulation of GRB030206 (annulus)
  79. IPN triangulation of GRB030208 (annulus)
  80. GRB 030204: Optical Observations
  81. GRB030204 field photometry
  82. GRB020819: Kiso R and I band observations
  83. GRB030131: Candidate Optical Afterglow
  84. GRB 030115: Optical Observations
  85. GRB 030204, optical observations
  86. IPN triangulation of GRB030204 (small error box)
  87. IPN triangulation of GRB030202 (annulus)
  88. GRB 030131, optical observations
  89. GRB030131: Kiso optical limit for corrected position
  90. GRB030131: Optical limits for corrected position
  91. GRB 030131: afterglow candidate
  92. GRB 030115, late-time optical observations
  93. Type Ic SN2003L (SN/GRB?), optical spectrum
  94. GRB030131: Kiso Observations
  95. GRB 020819: Host galaxy at Radio Position
  96. IPN triangulation of GRB030131 - CORRECTION
  97. GRB 020819: afterglow candidate
  98. IPN triangulation of GRB030131
  99. GRB030131: Optical limit
  100. GRB 030131 optical observations

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