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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"

45438 results found.

  1. GRB990123, Optical BVRI Observations
  2. GRB 990123: near-infrared observations.
  3. GRB990123, OSSE observations
  4. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  5. GRB990123: NIR Observation
  6. GRB990123, ASCA X-ray observation of afterglow
  7. "GRB 990123: New BV Observations"
  8. GRB 990123 Optical Follow-Up
  9. GRB 990123; Addendum to GCN 223
  10. GRB 990123: BATSE Observations
  11. GRB 990123 Keck Spectrum update
  12. GRB990123 IPN annulus
  13. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  14. GRB990123 Optical Observations
  15. GRB 990123 Spectroscopic Redshifts
  16. GRB 990123: New Optical Observations, Decay Measure
  17. GRB 990123 Optical Follow-Up
  18. GRB 990123: Possible Gravitationally Lensed Burst?
  19. GRB990123, optical observation
  20. GRB 990123 optical observations
  21. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  22. GRB 990123 radio observations
  23. GRB 990123, new radio source
  24. GRB990123 optical observations
  25. GRB990123, Optical observation
  26. GRB 990123: Optical Decay Slope
  27. GRB 990123 r-band photometry
  28. GRB 990123 Optical Follow-up
  29. GRB990123, early optical counterpart detection
  30. GRB990123 Optical Observation
  31. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  32. GRB990123, refined SAX-WFC position
  33. GRB 990123: Bright New Source, Possible Optical Transient
  34. GRB 990123, Radio observations
  35. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  36. SN 1999E & GRB 980919
  37. Possible identification of SN1999E with GRB980910
  38. Optical Observations of GRB 981220
  39. GRB 981226: radio variable
  40. GRB981220
  41. GRB981220, Correction to GCN 179
  42. GRB981220, Optical Observations
  43. GRB 981220 Optical observations
  44. GRB 981226 Optical Observations
  45. GRB 980613: Spectroscopy of the host galaxy
  46. GRB981226, sub-millimeter observations
  47. GRB981220, sub-millimeter observations
  48. GRB 981220 and GRB 981226, optical observations
  49. GRB981226 Optical Observations
  50. GRB981226 BeppoSAX follow up
  51. GRB 981226 radio observations
  52. GRB 981226
  53. GRB 981226 optical observations
  54. radio observations of GRB 981226
  55. GRB981220 B, R and I band observations
  56. GRB981226, BeppoSAX-NFI follow-up
  57. Optical Observations of GRB981226
  58. GRB 981220:Optical Observations
  59. GRB 981220 optical R and I observations
  60. GRB981226, BeppoSAX Christmas GRB
  61. GRB 981226 - Infrared Observations
  62. GRB 981226 optical observations
  63. GRB 981220
  64. GRB 981220, radio observations
  65. GRB981226 Optical Observation
  66. GRB 981220, radio observations
  67. GRB 981220: BeppoSAX/GRBM results
  68. GRB981220 I-band Observations
  69. GRB981220 Optical Observations
  70. GRB 981220
  71. GRB 981220 Optical Observations
  72. GRB 981220, optical observations
  73. GRB 980326/Host Galaxy
  74. GRB981220 IPN error box
  75. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  76. BeppoSAX NFI Observation of GRB980425
  77. GRB980329 R,I flux calibration and R,I,K upper limits
  78. GRB980425 Optical Follow-up
  79. GRB980425: X-ray revised positions
  80. GRB 980923 BATSE Observations
  81. SGR1900+14, BeppoSAX-GRBM observations
  82. GRB980703 Very Long Baseline Interferometry
  83. GRB970508 optical observations
  84. GRB971214, association with a Galactic star?
  85. Optical Observations of the Host Galaxy of GRB 980519
  86. GRB980519, Optical Observations
  87. GRB980703, Host galaxy multicolor photometry
  88. GRB980703 - BeppoSAX/GRBM detection
  89. GRB 980703 (NFI observations)
  90. GRB980703 optical photometry
  91. GRB 980703: BATSE Observations
  92. GRB980703 optical observations
  93. GRB980703: Radio transient
  94. GRB980703 H-band Observations
  95. GRB 980703: Spectrum of the proposed optical counterpart
  96. RXTE Observation of GRB 980706
  97. GRB980703: Spectrum of the proposed optical counterpart
  98. GRB980703 Transient Optical Follow-Up
  99. GRB980703: LOTIS observation at early times
  100. GRB980613 Optical Observations

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