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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"

36146 results found.

  1. GRB 030329: OT observations at Kanazawa
  2. GRB030329 15 GHz radio observation
  3. GRB 030329 RBO V Optical Observations
  4. GRB 030329, optical photometry
  5. GRB030329: Near Infrared Observations
  6. 030331 NOT A GRB
  7. INTEGRAL GRB 030331
  8. GRB 030324: Optical and NIR Observations
  9. GRB 030328, optical photometry
  10. GRB030329: R band light curve by MASTER
  11. GRB030329 - Light curve flattening
  12. GRB 030329: SARA Optical Observations
  13. GRB 030324, optical search
  14. GRB030329 - near contemporaneous optical limits from CONCAM
  15. GRB 030329, optical observations
  16. GRB 030329: Light curve observed during the change of its slope.
  17. GRB030329, BVRcIc field photometry
  18. GRB030329, SPM optical observations
  19. GRB 030329: Optical Decay
  20. Redshift of GRB 030329
  21. GRB030329: ROTSE network observes steepening of decay curve
  22. GRB 030329, optical photometry
  23. GRB 030329: Optical decay and synthesis
  24. GRB 030329: Radio Observations
  25. GRB 030329, optical spectroscopy
  26. GRB 030329: still bright
  27. GRB 030329: Optical pre-Imaging
  28. GRB 030329: visual observations
  29. GRB 030329: Upper limit from 5.6 hours before trigger
  30. GRB030328: R optical observation
  31. GRB 030323: Gemini South VRI obsevations.
  32. GRB030329: Optical observations
  33. GRB 030329, R-band observations, supplement
  34. GRB030329:optical observations by MASTER
  35. GRB 030329: optical observations
  36. GRB 030329, R-band observations
  37. GRB 030329: OT B and R photometry, decline rate
  38. GRB030329: Upper limits from recent and historical observations.
  39. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  40. RXTE detection of GRB 030329 afterglow
  41. GRB 030329: Optical Afterglow Observations
  42. GRB 030329: precise position from Kyoto images
  43. GRB 030328 Optical Observations
  44. GRB 030328: Optical observations
  45. GRB 030328: optical observations
  46. GRB 030329: Optical afterglow fading
  47. GRB 030329 follow-up
  48. GRB 030329: Optical afterglow candidate
  49. GRB 030329: OT candidate
  50. GRB 030329: Optical afterglow candidate
  51. GRB 030328: OT photometry
  52. VLT spectra of GRB 030328
  53. GRB 030328, optical spectroscopy
  54. GRB 030328, optical observations
  55. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  56. GRB 030328: Optical observations
  57. Re: GRB 030328: Finding chart
  58. GRB 030328: Finding chart
  59. GRB 030328: Optical afterglow candidate
  60. GRB030131, BVRcIc field photometry
  61. Possible GRB030323 localized by INTEGRAL
  62. IPN triangulation of GRB030325 (final analysis)
  63. IPN triangulation of GRB030326 (single small error box)
  64. GRB 030323: SARA Optical Observations
  65. IPN triangulation of GRB030325 (single small error box)
  66. GRB030324, optical observations
  67. IPN triangulation of GRB030325 (two small error boxes)
  68. GRB 030324: TAROT optical observations
  69. GRB 030324 (HETE #2641): Optical observations
  70. GRB030324, Optical Observations
  71. GRB030323: Upper limits from recent and historical observations.
  72. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  73. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  74. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  75. VLT/FORS2 spectra of GRB 030323
  76. GRB030323, ROTSE-III detection of possible optical counterpart
  77. GRB030323, optical observations
  78. GRB030324, BVRcIc field photometry
  79. GRB030323, possible optical counterpart
  80. GRB030323, BVRcIc field calibration
  81. GRB 030324 optical observations
  82. GRB 030320: Optical Observations
  83. GRB 030324, optical observations
  84. IPN triangulation of GRB030320B (annulus)
  85. IPN triangulation of GRB030320 (small error box)
  86. IPN triangulation of GRB030320
  87. Possible GRB 030320 localized by INTEGRAL
  88. IPN upper limit to a GRB associated with SN2003L
  89. IPN triangulation of GRB030317 (annulus)
  90. IPN triangulation of GRB030307 (annulus)
  91. GRB 030227: Optical limit at RIKEN
  92. GRB 030226 Optical observations
  93. IPN triangulation of GRB030306 (single small error box - REVISED)
  94. GRB030226: Optical observations at Asiago
  95. IPN triangulation of GRB030306 (single small error box)
  96. IPN triangulation of GRB030306 (two small error boxes)
  97. IPN triangulation of GRB030306 (intense; annulus only so far)
  98. GRB 030226: Optical observations
  99. IPN triangulation of GRB030304 (annulus)
  100. GRB 030227: Optical observations

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