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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"

42617 results found.

  1. IPN triangulation of GRB030325 (single small error box)
  2. GRB030324, optical observations
  3. GRB030324, optical observations
  4. IPN triangulation of GRB030325 (two small error boxes)
  5. GRB 030324: TAROT optical observations
  6. GRB030323: V, R, I photometry
  7. GRB030324, Optical Observations
  8. GRB030323: Upper limits from recent and historical observations.
  9. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  10. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  11. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  12. VLT/FORS2 spectra of GRB 030323
  13. GRB030323, ROTSE-III detection of possible optical counterpart
  14. GRB030323, optical observations
  15. GRB030324, BVRcIc field photometry
  16. GRB030323, possible optical counterpart
  17. GRB030323, BVRcIc field calibration
  18. GRB 030324 optical observations
  19. GRB 030320: Optical Observations
  20. GRB 030324, optical observations
  21. IPN triangulation of GRB030320B (annulus)
  22. IPN triangulation of GRB030320 (small error box)
  23. IPN triangulation of GRB030320
  24. Possible GRB 030320 localized by INTEGRAL
  25. GRB030226, addendum to GCN 1892
  26. IPN upper limit to a GRB associated with SN2003L
  27. IPN triangulation of GRB030317 (annulus)
  28. IPN triangulation of GRB030307 (annulus)
  29. GRB 030227: Optical limit at RIKEN
  30. GRB 030226 Optical observations
  31. IPN triangulation of GRB030306 (single small error box - REVISED)
  32. GRB030226: Optical observations at Asiago
  33. IPN triangulation of GRB030306 (single small error box)
  34. IPN triangulation of GRB030306 (two small error boxes)
  35. IPN triangulation of GRB030306 (intense; annulus only so far)
  36. GRB 030226: Optical observations
  37. GRB030226: Analysis of Chandra data
  38. IPN triangulation of GRB030304 (annulus)
  39. GRB 030227: Optical observations
  40. GRB030226, BVRc observations
  41. Chandra detection of the X-ray afterglow of GRB 030226
  42. GRB 030226, further optical/NIR imaging
  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. GRB 030227 optical afterglow
  50. 030302: NOT A GRB
  51. 030228: NOT A GRB
  52. GRB 030228, optical observations
  53. GRB 030226: Steep Decline
  54. GRB 030227: Confirmed Optical Afterglow (S1-A)
  55. GRB 030226: R band polarimetric observations
  56. GRB 030226: Optical observations
  57. GRB 030227: fading of candidate optical afterglow 'S1-A'
  58. GRB030227:Optical observations
  59. GRB 20030226: Upper limits from recent and historical observations
  60. GRB 030227, possible optical counterpart of XMM-Newton source
  61. GRB030227 - faint tentative OT candidate
  62. GRB 030226, optical observations
  63. XMM-Newton observation of GRB030227
  64. GRB030227: Kiso optical observations
  65. GRB 030227: Kyoto optical observation
  66. GRB 030226, optical light curve
  67. GRB 030226 spectroscopy
  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. GRB 030226, optical observations
  77. GRB030226: Optical decay index
  78. GRB 030226 Optical Spectra and R,I,z' Imaging
  79. GRB 030226, optical observations
  80. GRB 030226: Optical afterglow
  81. GRB030226: Candidate optical afterglow
  82. GRB 030217: Optical Observations at 4, 5, and 6 Days
  83. IPN triangulation of GRB030223 (annulus)
  84. IPN triangulation of GRB030220 (annulus)
  85. GRB: Non-Referencing of GCN Circulars.
  86. IPN triangulation of GRB030218 (annulus)
  87. GRB030217: optical observations
  88. IPN triangulation of GRB030217 (small error box)
  89. IPN triangulation of GRB030215C (annulus)
  90. IPN triangulation of GRB030217 (annulus)
  91. IPN triangulation of GRB030216 (annulus)
  92. IPN triangulation of GRB030215A and GRB030215B (annuli)
  93. GRB030115, WSRT radio observations - correction to GCN 1864
  94. GRB 030131: marginal optical detection
  95. GCN/INTEGRAL Mistake Fixed
  96. GRB030115, WSRT radio observations
  97. IPN triangulation of GRB030206 (annulus)
  98. IPN triangulation of GRB030208 (annulus)
  99. GRB 030204: Optical Observations
  100. GRB030204 field photometry

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