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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"

36143 results found.

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

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