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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"

26305 results found.

  1. GRB030329: R and B observations
  2. GRB 030329, optical observations
  3. GRB030329: Optical observations
  4. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  5. GRB030329a: detection by Konus-Wind
  6. GRB030329b: detection by Konus-Wind and Helicon-CoronasF
  7. GRB 030329: Light curve observed during the change of its slope.
  8. GRB030329, SPM optical observations
  9. GRB 030329: Optical Decay
  10. GRB030329: ROTSE network observes steepening of decay curve
  11. GRB 030329, optical photometry
  12. GRB030329 optical observations
  13. GRB 030329: Optical pre-Imaging
  14. GRB 030329: visual observations
  15. GRB030328: R optical observation
  16. GRB030328: X-ray Afterglow Observed with Chandra
  17. GRB030329: Optical observations
  18. GRB030329 optical observations
  19. GRB030329:optical observations by MASTER
  20. GRB 030329: optical observations
  21. GRB 030329, R-band observations
  22. GRB030329: Upper limits from recent and historical observations.
  23. GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
  24. RXTE detection of GRB 030329 afterglow
  25. GRB 030329: Optical Afterglow Observations
  26. GRB 030328 Optical Observations
  27. GRB030328: Decay index
  28. GRB 030328: Optical observations
  29. GRB 030328: optical observations
  30. GRB 030329 follow-up
  31. GRB 030329: OT candidate
  32. GRB030328: optical spectroscopy at TNG
  33. GRB030328: optical photometry at the TNG
  34. VLT spectra of GRB 030328
  35. GRB 030328, optical observations
  36. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  37. GRB030323 optical observations
  38. GRB030131, BVRcIc field photometry
  39. Possible GRB030323 localized by INTEGRAL
  40. GRB030323: Detection on 2003/03/24
  41. IPN triangulation of GRB030326 (single small error box)
  42. GRB 030323: SARA Optical Observations
  43. GRB030324, optical observations
  44. GRB030324, optical observations
  45. IPN triangulation of GRB030325 (two small error boxes)
  46. GRB030323: V, R, I photometry
  47. GRB030323: Upper limits from recent and historical observations.
  48. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  49. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  50. GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
  51. GRB030323, ROTSE-III detection of possible optical counterpart
  52. GRB030323, optical observations
  53. GRB030323, possible optical counterpart
  54. GRB 030320: Optical Observations
  55. IPN triangulation of GRB030320B (annulus)
  56. IPN triangulation of GRB030320 (small error box)
  57. Possible GRB 030320 localized by INTEGRAL
  58. GRB030226, addendum to GCN 1892
  59. IPN upper limit to a GRB associated with SN2003L
  60. IPN triangulation of GRB030317 (annulus)
  61. IPN triangulation of GRB030307 (annulus)
  62. GRB 030227: Optical limit at RIKEN
  63. IPN triangulation of GRB030306 (single small error box - REVISED)
  64. GRB030226: Optical observations at Asiago
  65. IPN triangulation of GRB030306 (intense; annulus only so far)
  66. GRB 030226: Optical observations
  67. GRB030226: Analysis of Chandra data
  68. IPN triangulation of GRB030304 (annulus)
  69. GRB 030227: Optical observations
  70. GRB030226, BVRc observations
  71. Chandra detection of the X-ray afterglow of GRB 030226
  72. GRB 030226, further optical/NIR imaging
  73. GRB030227: Kiso optical upper limit
  74. IPN triangulation of GRB030301 (annulus)
  75. IPN triangulation of GRB030228 (annulus)
  76. GRB030226, BVRcIc field calibration
  77. GRB 030227 optical afterglow
  78. GRB 030226: Steep Decline
  79. GRB 030227: Confirmed Optical Afterglow (S1-A)
  80. GRB 030226: Optical observations
  81. GRB 030227: fading of candidate optical afterglow 'S1-A'
  82. GRB 20030226: Upper limits from recent and historical observations
  83. GRB 030227, possible optical counterpart of XMM-Newton source
  84. GRB 030226, optical observations
  85. GRB030227: Kiso optical observations
  86. GRB 030226, optical light curve
  87. GRB030227 localized by INTEGRAL
  88. Possible break in the GRB 030226 light curve
  89. IPN triangulation of GRB030225 (annulus)
  90. GRB 030226: Confirmed decay index
  91. GRB030226: ESI spectroscopy
  92. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  93. GRB 030226: Optical afterglow
  94. GRB030226: Candidate optical afterglow
  95. IPN triangulation of GRB030223 (annulus)
  96. IPN triangulation of GRB030220 (annulus)
  97. GRB: Non-Referencing of GCN Circulars.
  98. IPN triangulation of GRB030218 (annulus)
  99. GRB030217: optical observations
  100. IPN triangulation of GRB030217 (small error box)

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