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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"

37943 results found.

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

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