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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"

43595 results found.

  1. GRB 030329, R-band observations
  2. GRB 030329: OT B and R photometry, decline rate
  3. GRB030329: Upper limits from recent and historical observations.
  4. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  5. RXTE detection of GRB 030329 afterglow
  6. GRB 030329: Optical Afterglow Observations
  7. GRB 030329: precise position from Kyoto images
  8. GRB 030328 Optical Observations
  9. GRB030328: Decay index
  10. GRB 030328: Optical observations
  11. GRB 030328: optical observations
  12. GRB 030329: Optical afterglow fading
  13. GRB 030329 follow-up
  14. GRB 030329: Optical afterglow candidate
  15. GRB 030329: OT candidate
  16. GRB 030329: Optical afterglow candidate
  17. GRB 030328: OT photometry
  18. GRB030328: optical spectroscopy at TNG
  19. GRB030328: optical photometry at the TNG
  20. VLT spectra of GRB 030328
  21. GRB 030328, optical spectroscopy
  22. GRB 030328, optical observations
  23. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  24. GRB 030328: Optical observations
  25. Re: GRB 030328: Finding chart
  26. GRB 030328: Finding chart
  27. GRB 030328: Optical afterglow candidate
  28. GRB030324 optical observation
  29. GRB030131, BVRcIc field photometry
  30. Possible GRB030323 localized by INTEGRAL
  31. IPN triangulation of GRB030325 (final analysis)
  32. GRB030323: Detection on 2003/03/24
  33. IPN triangulation of GRB030326 (single small error box)
  34. GRB 030323: SARA Optical Observations
  35. IPN triangulation of GRB030325 (single small error box)
  36. GRB030324, optical observations
  37. GRB030324, optical observations
  38. IPN triangulation of GRB030325 (two small error boxes)
  39. GRB 030324: TAROT optical observations
  40. GRB030323: V, R, I photometry
  41. GRB030324, Optical Observations
  42. GRB030323: Upper limits from recent and historical observations.
  43. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  44. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  45. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  46. VLT/FORS2 spectra of GRB 030323
  47. GRB030323, ROTSE-III detection of possible optical counterpart
  48. GRB030323, optical observations
  49. GRB030324, BVRcIc field photometry
  50. GRB030323, possible optical counterpart
  51. GRB030323, BVRcIc field calibration
  52. GRB 030324 optical observations
  53. GRB 030320: Optical Observations
  54. GRB 030324, optical observations
  55. IPN triangulation of GRB030320B (annulus)
  56. IPN triangulation of GRB030320 (small error box)
  57. IPN triangulation of GRB030320
  58. Possible GRB 030320 localized by INTEGRAL
  59. GRB030226, addendum to GCN 1892
  60. IPN upper limit to a GRB associated with SN2003L
  61. IPN triangulation of GRB030317 (annulus)
  62. IPN triangulation of GRB030307 (annulus)
  63. GRB 030227: Optical limit at RIKEN
  64. GRB 030226 Optical observations
  65. IPN triangulation of GRB030306 (single small error box - REVISED)
  66. GRB030226: Optical observations at Asiago
  67. IPN triangulation of GRB030306 (single small error box)
  68. IPN triangulation of GRB030306 (two small error boxes)
  69. IPN triangulation of GRB030306 (intense; annulus only so far)
  70. GRB 030226: Optical observations
  71. GRB030226: Analysis of Chandra data
  72. IPN triangulation of GRB030304 (annulus)
  73. GRB 030227: Optical observations
  74. GRB030226, BVRc observations
  75. Chandra detection of the X-ray afterglow of GRB 030226
  76. GRB 030226, further optical/NIR imaging
  77. GRB 030226: Ic Observations
  78. GRB030227: Kiso optical upper limit
  79. IPN triangulation of GRB030301 (annulus)
  80. IPN triangulation of GRB030228 (annulus)
  81. GRB030227, BVRcIc field photometry
  82. GRB030226, BVRcIc field calibration
  83. GRB 030227 optical afterglow
  84. 030302: NOT A GRB
  85. 030228: NOT A GRB
  86. GRB 030228, optical observations
  87. GRB 030226: Steep Decline
  88. GRB 030227: Confirmed Optical Afterglow (S1-A)
  89. GRB 030226: R band polarimetric observations
  90. GRB 030226: Optical observations
  91. GRB 030227: fading of candidate optical afterglow 'S1-A'
  92. GRB030227:Optical observations
  93. GRB 20030226: Upper limits from recent and historical observations
  94. GRB 030227, possible optical counterpart of XMM-Newton source
  95. GRB030227 - faint tentative OT candidate
  96. GRB 030226, optical observations
  97. XMM-Newton observation of GRB030227
  98. GRB030227: Kiso optical observations
  99. GRB 030227: Kyoto optical observation
  100. GRB 030226, optical light curve

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