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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"

37509 results found.

  1. GRB030329:optical observations by MASTER
  2. GRB 030329: optical observations
  3. GRB 030329, R-band observations
  4. GRB 030329: OT B and R photometry, decline rate
  5. GRB030329: Upper limits from recent and historical observations.
  6. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  7. RXTE detection of GRB 030329 afterglow
  8. GRB 030329: Optical Afterglow Observations
  9. GRB 030329: precise position from Kyoto images
  10. GRB 030328 Optical Observations
  11. GRB 030328: Optical observations
  12. GRB 030328: optical observations
  13. GRB 030329: Optical afterglow fading
  14. GRB 030329 follow-up
  15. GRB 030329: Optical afterglow candidate
  16. GRB 030329: OT candidate
  17. GRB 030329: Optical afterglow candidate
  18. GRB 030328: OT photometry
  19. VLT spectra of GRB 030328
  20. GRB 030328, optical spectroscopy
  21. GRB 030328, optical observations
  22. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  23. GRB 030328: Optical observations
  24. Re: GRB 030328: Finding chart
  25. GRB 030328: Finding chart
  26. GRB 030328: Optical afterglow candidate
  27. GRB030131, BVRcIc field photometry
  28. Possible GRB030323 localized by INTEGRAL
  29. IPN triangulation of GRB030325 (final analysis)
  30. IPN triangulation of GRB030326 (single small error box)
  31. GRB 030323: SARA Optical Observations
  32. IPN triangulation of GRB030325 (single small error box)
  33. GRB030324, optical observations
  34. IPN triangulation of GRB030325 (two small error boxes)
  35. GRB 030324: TAROT optical observations
  36. GRB 030324 (HETE #2641): Optical observations
  37. GRB030324, Optical Observations
  38. GRB030323: Upper limits from recent and historical observations.
  39. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  40. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  41. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  42. VLT/FORS2 spectra of GRB 030323
  43. GRB030323, ROTSE-III detection of possible optical counterpart
  44. GRB030323, optical observations
  45. GRB030324, BVRcIc field photometry
  46. GRB030323, possible optical counterpart
  47. GRB030323, BVRcIc field calibration
  48. GRB 030324 optical observations
  49. GRB 030320: Optical Observations
  50. GRB 030324, optical observations
  51. IPN triangulation of GRB030320B (annulus)
  52. IPN triangulation of GRB030320 (small error box)
  53. IPN triangulation of GRB030320
  54. Possible GRB 030320 localized by INTEGRAL
  55. IPN upper limit to a GRB associated with SN2003L
  56. IPN triangulation of GRB030317 (annulus)
  57. IPN triangulation of GRB030307 (annulus)
  58. GRB 030227: Optical limit at RIKEN
  59. GRB 030226 Optical observations
  60. IPN triangulation of GRB030306 (single small error box - REVISED)
  61. GRB030226: Optical observations at Asiago
  62. IPN triangulation of GRB030306 (single small error box)
  63. IPN triangulation of GRB030306 (two small error boxes)
  64. IPN triangulation of GRB030306 (intense; annulus only so far)
  65. GRB 030226: Optical observations
  66. IPN triangulation of GRB030304 (annulus)
  67. GRB 030227: Optical observations
  68. GRB030226, BVRc observations
  69. Chandra detection of the X-ray afterglow of GRB 030226
  70. GRB 030226, further optical/NIR imaging
  71. GRB030227, optical observations
  72. GRB 030226: Ic Observations
  73. GRB030227: Kiso optical upper limit
  74. IPN triangulation of GRB030301 (annulus)
  75. IPN triangulation of GRB030228 (annulus)
  76. GRB030227, BVRcIc field photometry
  77. GRB030226, BVRcIc field calibration
  78. GRB 030227 optical afterglow
  79. 030302: NOT A GRB
  80. 030228: NOT A GRB
  81. GRB 030228, optical observations
  82. GRB 030226: Steep Decline
  83. GRB 030227: Confirmed Optical Afterglow (S1-A)
  84. GRB 030226: R band polarimetric observations
  85. GRB 030226: Optical observations
  86. GRB 030227: fading of candidate optical afterglow 'S1-A'
  87. GRB030227:Optical observations
  88. GRB 20030226: Upper limits from recent and historical observations
  89. GRB 030227, possible optical counterpart of XMM-Newton source
  90. GRB030227 - faint tentative OT candidate
  91. GRB 030226, optical observations
  92. GRB030227: Kiso optical observations
  93. GRB 030227: Kyoto optical observation
  94. GRB 030226, optical light curve
  95. GRB 030226 spectroscopy
  96. Possible break in the GRB 030226 light curve
  97. GRB 030226 : Predicted light curve
  98. IPN triangulation of GRB030225 (annulus)
  99. GRB 030226: Confirmed decay index
  100. GRB030226: ESI spectroscopy

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