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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"

44436 results found.

  1. IPN triangulation of GRB030325 (two small error boxes)
  2. GRB 030324: TAROT optical observations
  3. GRB030323: V, R, I photometry
  4. GRB 030324 (HETE #2641): Optical observations
  5. GRB030324, Optical Observations
  6. GRB030323: Upper limits from recent and historical observations.
  7. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  8. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  9. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  10. VLT/FORS2 spectra of GRB 030323
  11. GRB030323, ROTSE-III detection of possible optical counterpart
  12. GRB030323, optical observations
  13. GRB030324, BVRcIc field photometry
  14. GRB030323, possible optical counterpart
  15. GRB030323, BVRcIc field calibration
  16. GRB 030324 optical observations
  17. GRB 030320: Optical Observations
  18. GRB 030324, optical observations
  19. IPN triangulation of GRB030320B (annulus)
  20. IPN triangulation of GRB030320 (small error box)
  21. IPN triangulation of GRB030320
  22. Possible GRB 030320 localized by INTEGRAL
  23. GRB030226, addendum to GCN 1892
  24. IPN upper limit to a GRB associated with SN2003L
  25. IPN triangulation of GRB030317 (annulus)
  26. IPN triangulation of GRB030307 (annulus)
  27. GRB 030227: Optical limit at RIKEN
  28. GRB 030226 Optical observations
  29. IPN triangulation of GRB030306 (single small error box - REVISED)
  30. GRB030226: Optical observations at Asiago
  31. IPN triangulation of GRB030306 (single small error box)
  32. IPN triangulation of GRB030306 (two small error boxes)
  33. IPN triangulation of GRB030306 (intense; annulus only so far)
  34. GRB 030226: Optical observations
  35. GRB030226: Analysis of Chandra data
  36. IPN triangulation of GRB030304 (annulus)
  37. GRB 030227: Optical observations
  38. GRB030226, BVRc observations
  39. Chandra detection of the X-ray afterglow of GRB 030226
  40. GRB 030226, further optical/NIR imaging
  41. GRB030227, optical observations
  42. GRB 030226: Ic Observations
  43. GRB030227: Kiso optical upper limit
  44. IPN triangulation of GRB030301 (annulus)
  45. IPN triangulation of GRB030228 (annulus)
  46. GRB030227, BVRcIc field photometry
  47. GRB030226, BVRcIc field calibration
  48. 030302: NOT A GRB
  49. 030228: NOT A GRB
  50. GRB 030228, optical observations
  51. GRB 030226: Steep Decline
  52. GRB 030227: Confirmed Optical Afterglow (S1-A)
  53. GRB 030226: R band polarimetric observations
  54. GRB 030226: Optical observations
  55. GRB 030227: fading of candidate optical afterglow 'S1-A'
  56. GRB030227:Optical observations
  57. GRB 20030226: Upper limits from recent and historical observations
  58. GRB 030227, possible optical counterpart of XMM-Newton source
  59. GRB030227 - faint tentative OT candidate
  60. GRB 030226, optical observations
  61. XMM-Newton observation of GRB030227
  62. GRB030227: Kiso optical observations
  63. GRB 030227: Kyoto optical observation
  64. GRB 030226, optical light curve
  65. GRB 030226 spectroscopy
  66. GRB030227: refined INTEGRAL position
  67. GRB030227 localized by INTEGRAL
  68. Possible break in the GRB 030226 light curve
  69. GRB 030226 : Predicted light curve
  70. GRB030226: optical observation
  71. IPN triangulation of GRB030225 (annulus)
  72. GRB 030226: Confirmed decay index
  73. GRB030226: ESI spectroscopy
  74. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  75. GRB 030226 simultaneous optical observations
  76. Two absorption systems in GRB 030226
  77. GRB 030226, optical observations
  78. GRB030226: optical observations and refined redshift
  79. GRB030226: Optical decay index
  80. GRB 030226 Optical Spectra and R,I,z' Imaging
  81. GRB 030226, optical observations
  82. GRB 030226: Optical afterglow
  83. GRB030226: Candidate optical afterglow
  84. GRB 030217: Optical Observations at 4, 5, and 6 Days
  85. IPN triangulation of GRB030223 (annulus)
  86. IPN triangulation of GRB030220 (annulus)
  87. GRB: Non-Referencing of GCN Circulars.
  88. IPN triangulation of GRB030218 (annulus)
  89. GRB030217: optical observations
  90. IPN triangulation of GRB030217 (small error box)
  91. IPN triangulation of GRB030215C (annulus)
  92. IPN triangulation of GRB030217 (annulus)
  93. IPN triangulation of GRB030216 (annulus)
  94. IPN triangulation of GRB030215A and GRB030215B (annuli)
  95. GRB030115, WSRT radio observations - correction to GCN 1864
  96. GRB 030131: marginal optical detection
  97. GCN/INTEGRAL Mistake Fixed
  98. GRB030115, WSRT radio observations
  99. IPN triangulation of GRB030206 (annulus)
  100. IPN triangulation of GRB030208 (annulus)

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