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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"

22046 results found.

  1. GRB030329 optical observations
  2. GRB030329:optical observations by MASTER
  3. GRB 030329: optical observations
  4. GRB 030329, R-band observations
  5. GRB030329: Upper limits from recent and historical observations.
  6. GRB 030329: Optical Afterglow Observations
  7. GRB 030328 Optical Observations
  8. GRB030328: Decay index
  9. GRB 030328: Optical observations
  10. GRB 030328: optical observations
  11. GRB 030329: Optical afterglow fading
  12. GRB 030329 follow-up
  13. GRB 030329: Optical afterglow candidate
  14. GRB 030328: OT photometry
  15. GRB030328: optical spectroscopy at TNG
  16. GRB030328: optical photometry at the TNG
  17. GRB 030328, optical observations
  18. GRB 030328: Optical observations
  19. GRB 030328: Optical afterglow candidate
  20. GRB030323 optical observations
  21. GRB030323: Detection on 2003/03/24
  22. GRB 030323: SARA Optical Observations
  23. GRB030324, optical observations
  24. GRB030324, optical observations
  25. GRB 030324: TAROT optical observations
  26. GRB030323: V, R, I photometry
  27. GRB 030324 (HETE #2641): Optical observations
  28. GRB030324, Optical Observations
  29. GRB030323: Upper limits from recent and historical observations.
  30. GRB030323, ROTSE-III detection of possible optical counterpart
  31. GRB030323, optical observations
  32. GRB030324, BVRcIc field photometry
  33. GRB030323, possible optical counterpart
  34. GRB030323, BVRcIc field calibration
  35. GRB 030324 optical observations
  36. GRB 030320: Optical Observations
  37. GRB 030324, optical observations
  38. Possible GRB 030320 localized by INTEGRAL
  39. GRB030226, addendum to GCN 1892
  40. GRB 030226 Optical observations
  41. GRB030226: Optical observations at Asiago
  42. IPN triangulation of GRB030306 (intense; annulus only so far)
  43. GRB 030226: Optical observations
  44. GRB 030227: Optical observations
  45. GRB030226, BVRc observations
  46. GRB 030226, further optical/NIR imaging
  47. GRB030227, optical observations
  48. GRB 030226: Ic Observations
  49. GRB 030228, optical observations
  50. GRB 030226: Steep Decline
  51. GRB 030226: R band polarimetric observations
  52. GRB 030226: Optical observations
  53. GRB030227:Optical observations
  54. GRB 20030226: Upper limits from recent and historical observations
  55. GRB 030227, possible optical counterpart of XMM-Newton source
  56. GRB030227 - faint tentative OT candidate
  57. GRB 030226, optical observations
  58. GRB030227: Kiso optical observations
  59. GRB 030226, optical light curve
  60. GRB030226: optical observation
  61. GRB030226: ESI spectroscopy
  62. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  63. GRB 030226 simultaneous optical observations
  64. GRB 030226, optical observations
  65. GRB030226: optical observations and refined redshift
  66. GRB030226: Optical decay index
  67. GRB 030226, optical observations
  68. GRB030226: Candidate optical afterglow
  69. GRB 030217: Optical Observations at 4, 5, and 6 Days
  70. GRB030217: optical observations
  71. GRB030115, WSRT radio observations - correction to GCN 1864
  72. GRB 030131: marginal optical detection
  73. GRB030115, WSRT radio observations
  74. GRB 030204: Optical Observations
  75. GRB020819: Kiso R and I band observations
  76. GRB030131: Candidate Optical Afterglow
  77. GRB 030115: Optical Observations
  78. GRB 030204, optical observations
  79. GRB 030131, optical observations
  80. GRB030131: Optical limits for corrected position
  81. GRB 030131: afterglow candidate
  82. GRB 030115, late-time optical observations
  83. Type Ic SN2003L (SN/GRB?), optical spectrum
  84. GRB030131: Kiso Observations
  85. GRB 020819: Host galaxy at Radio Position
  86. GRB030131: Optical limit
  87. GRB 030131 optical observations
  88. GRB 030131 optical observations
  89. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  90. Type Ic SN2003L (SN/GRB?) Radio Observations
  91. GRB030115 submm upper limit
  92. GRB 030115: Further IR observations with IRSF/SIRIUS
  93. GRB 030115: Radio detection of IR candidate
  94. GRB 030115, simultaneous observations by BOOTES-1
  95. GRB 030115: IR observations with IRSF/SIRIUS
  96. GRB 021211: R-band observations at late-time
  97. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  98. GRB 030115 : Possible IR counterpart
  99. GRB 030115: Radio Observations
  100. GRB030115: R-band observations at Asiago

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