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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"

35433 results found.

  1. GRB030329 - near contemporaneous optical limits from CONCAM
  2. GRB 030329, optical observations
  3. GRB 030329: Light curve observed during the change of its slope.
  4. GRB030329, BVRcIc field photometry
  5. GRB030329, SPM optical observations
  6. GRB 030329: Optical Decay
  7. Redshift of GRB 030329
  8. GRB030329: ROTSE network observes steepening of decay curve
  9. GRB 030329, optical photometry
  10. GRB 030329: Optical decay and synthesis
  11. GRB 030329: Radio Observations
  12. GRB 030329, optical spectroscopy
  13. GRB 030329: still bright
  14. GRB 030329: Optical pre-Imaging
  15. GRB 030329: visual observations
  16. GRB 030329: Upper limit from 5.6 hours before trigger
  17. GRB030328: R optical observation
  18. GRB 030323: Gemini South VRI obsevations.
  19. GRB030329: Optical observations
  20. GRB 030329, R-band observations, supplement
  21. GRB030329:optical observations by MASTER
  22. GRB 030329: optical observations
  23. GRB 030329, R-band observations
  24. GRB 030329: OT B and R photometry, decline rate
  25. GRB030329: Upper limits from recent and historical observations.
  26. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  27. RXTE detection of GRB 030329 afterglow
  28. GRB 030329: Optical Afterglow Observations
  29. GRB 030329: precise position from Kyoto images
  30. GRB 030328 Optical Observations
  31. GRB 030328: Optical observations
  32. GRB 030328: optical observations
  33. GRB 030329: Optical afterglow fading
  34. GRB 030329 follow-up
  35. GRB 030329: Optical afterglow candidate
  36. GRB 030329: OT candidate
  37. GRB 030329: Optical afterglow candidate
  38. GRB 030328: OT photometry
  39. VLT spectra of GRB 030328
  40. GRB 030328, optical spectroscopy
  41. GRB 030328, optical observations
  42. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  43. GRB 030328: Optical observations
  44. Re: GRB 030328: Finding chart
  45. GRB 030328: Finding chart
  46. GRB 030328: Optical afterglow candidate
  47. GRB030131, BVRcIc field photometry
  48. Possible GRB030323 localized by INTEGRAL
  49. IPN triangulation of GRB030325 (final analysis)
  50. IPN triangulation of GRB030326 (single small error box)
  51. GRB 030323: SARA Optical Observations
  52. IPN triangulation of GRB030325 (single small error box)
  53. GRB030324, optical observations
  54. IPN triangulation of GRB030325 (two small error boxes)
  55. GRB 030324: TAROT optical observations
  56. GRB 030324 (HETE #2641): Optical observations
  57. GRB030324, Optical Observations
  58. GRB030323: Upper limits from recent and historical observations.
  59. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  60. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  61. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  62. VLT/FORS2 spectra of GRB 030323
  63. GRB030323, ROTSE-III detection of possible optical counterpart
  64. GRB030323, optical observations
  65. GRB030324, BVRcIc field photometry
  66. GRB030323, possible optical counterpart
  67. GRB030323, BVRcIc field calibration
  68. GRB 030324 optical observations
  69. GRB 030320: Optical Observations
  70. GRB 030324, optical observations
  71. IPN triangulation of GRB030320B (annulus)
  72. IPN triangulation of GRB030320 (small error box)
  73. IPN triangulation of GRB030320
  74. Possible GRB 030320 localized by INTEGRAL
  75. IPN upper limit to a GRB associated with SN2003L
  76. IPN triangulation of GRB030317 (annulus)
  77. IPN triangulation of GRB030307 (annulus)
  78. GRB 030227: Optical limit at RIKEN
  79. GRB 030226 Optical observations
  80. IPN triangulation of GRB030306 (single small error box - REVISED)
  81. GRB030226: Optical observations at Asiago
  82. IPN triangulation of GRB030306 (single small error box)
  83. IPN triangulation of GRB030306 (two small error boxes)
  84. IPN triangulation of GRB030306 (intense; annulus only so far)
  85. GRB 030226: Optical observations
  86. IPN triangulation of GRB030304 (annulus)
  87. GRB 030227: Optical observations
  88. GRB030226, BVRc observations
  89. Chandra detection of the X-ray afterglow of GRB 030226
  90. GRB 030226, further optical/NIR imaging
  91. GRB030227, optical observations
  92. GRB 030226: Ic Observations
  93. GRB030227: Kiso optical upper limit
  94. IPN triangulation of GRB030301 (annulus)
  95. IPN triangulation of GRB030228 (annulus)
  96. GRB030227, BVRcIc field photometry
  97. GRB030226, BVRcIc field calibration
  98. GRB 030227 optical afterglow
  99. 030302: NOT A GRB
  100. 030228: NOT A GRB

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