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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').

10044 results found.

  1. GRB010326B: Localization by HETE (2nd GRB for this date)
  2. GRB010326: Refined Localization by HETE
  3. GRB010326: Localization by HETE
  4. Optical Observations of GRB 010324
  5. GRB 010222 - HEGRA GeV/TeV Observations
  6. GRB010222, possible increase of optical decay slope
  7. GRB 010220: Near-IR Observations
  8. GRB 010222: Near-IR Observations
  9. GRB010214, candidate optical afterglow
  10. GRB010214, optical observations
  11. J-Band Observation of GRB 010214.
  12. Possible InfraRed Transient of GRB 010214.
  13. GRB010214 Optical Observation
  14. GRB010213 detected by HETE
  15. GRB010126, TNG R-band observations
  16. Optical Observations of GRB 001018 at Keck
  17. H band observation of GRB 001212
  18. GRB 001109: deep JHK upper limits
  19. CORRECTION to XMM-Newton observation of GRB001025
  20. XMM-Newton observation of GRB001025
  21. V,R,I band observations of GRB000926
  22. The Likely Optical/Infrared Afterglow of GRB 001011
  23. Public availability of BeppoSAX data of GRB000926
  24. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  25. GRB 000926, Optical Decay
  26. GRB 000926, Optical Observations
  27. J and K band observations of GRB 000926
  28. GRB 000926, Optical Observation
  29. Optical candidate for GRB000926
  30. GRB000830, TNG B-band observations
  31. GRB000210, Optical observations
  32. Chandra Position of GRB000210
  33. GRB000812, TNG R-band observations
  34. GRB000801, VLT-Antu R-band observations
  35. GRB000630, optical observations
  36. GRB000418, HST/STIS Observations
  37. GRB000620, optical observations
  38. GRB000615: H-band observations
  39. GRB000620 Optical observations
  40. GRB000607, optical observations
  41. GRB000616 optical observations
  42. GRB 000615: NIR observations
  43. Optical Follow-up of GRB000529 Error Box
  44. GRB000528, optical observations at ESO
  45. Re: GRB000508B : Optical observations
  46. GRB 000424 Optical Observations
  47. GRB 000418, Optical Observation
  48. GRB000424 Optical Observations
  49. GRB 000418, Optical Observation
  50. GRB 000418, Optical Observation
  51. BeppoSAX GRB000424
  52. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  53. GRB 000301C: Optical Spectrum and Redshift
  54. GRB 000301C: Optical Spectrum and Redshift
  55. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  56. GRB000301C, optical R-band observations
  57. GRB 000301C: K' Observations
  58. GRB000301C - Host galaxy not detected in R (?)
  59. GRB 000301c near-IR observations
  60. GRB 000301C, Optical Color
  61. GRB 000301C, Optical Observation
  62. GRB 000301C, Optical Observation
  63. GRB 000115 Optical observations
  64. GRB 000115 Optical observations
  65. GRB 991216: J band spectrophotometry
  66. GRB991217/SAX J2303.2+0015, optical observations
  67. Chandra observation of the X-ray afterglow of GRB991216
  68. GRB 991208 Keck Spectroscopy
  69. GRB 991208 Infrared Detection
  70. GRB 991216: Comparison with DPOSS images
  71. R-band Observations of GRB991208 at TNG
  72. GRB991208, optical observations
  73. Optical Observations of GRB991105
  74. GRB991106, optical observation at SAO-RAS
  75. Revised BeppoSAX WFC position of GRB991105
  76. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  77. GRB 991014, radio observations
  78. GRB 991014, Optical Observations
  79. Optical Observations of GRB990907
  80. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  81. GRB990806 BeppoSAX follow up
  82. GRB 990806, Optical Observations
  83. GRB 990806, optical observations
  84. GRB 990806, Optical Observations
  85. GRB990806 UBVRIJHK observations
  86. BeppoSAX ALERT GRB990806: Summer GRB
  87. VLT spectrum of GRB990712
  88. Updated Astrometry for the IR Counterpart of GRB990705
  89. Infrared and Optical Observations of GRB990705
  90. GRB990704 radio and optical observations
  91. GRB 990704 X-ray Observations
  92. GRB990705: Intriguing Positional Coincidences
  93. Optical Observations of GRB990627
  94. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  95. GRB 990506 optical observation
  96. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  97. BeppoSAX: A new fast X-ray transient
  98. GRB 990506 R band observations
  99. VLT spectrum of GRB990510
  100. GRB 990510: Broad Band Break

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