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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"

35426 results found.

  1. GRB990316, Optical observations
  2. GRB 990316 optical observations
  3. GRB990316: simultaneous optical observation
  4. ASM/IPN error box for GRB 990308 (BATSE #7457)
  5. GRB990308 not a new SGR
  6. GRB 990308a and GRB 990308b
  7. GRB990308 (Trig. 7457), optical observations
  8. GRB981220, IPN localization
  9. GRB 981220, radio observations
  10. GRB 990123, Field Photometry
  11. GRB 990217 Optical Observations
  12. GRB 990217, radio observations
  13. Optical Observations of GRB990217
  14. GRB990123: Caltech STIS Photometry and Images
  15. GRB990123 observations
  16. GRB990123, Optical Observation
  17. GRB 990123: Discovery of the Probable Host Galaxy
  18. GRB 990123: Reduced HST Images
  19. For Immediate Posting to GCN - HST Data GRB 990123 Available
  20. GRB19990123 observations
  21. GRB 990123: BVRI standards in the field
  22. GRB 990123: Updated Keck Spectroscopy Results
  23. GRB981220, field photometry
  24. GRB 990123 NOT Spectrum Update
  25. GRB990123, Optical observation
  26. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  27. GRB 990123: Publicly available reduced HST images
  28. GRB990123, Upcoming HST Service Observations
  29. GRB 990123: New Constraints on Possible Foreground Galaxies
  30. GRB990123 Optical Observations
  31. GRB990123, Probability of gravitational lensing
  32. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  33. GRB 990123: Continued Radio Observations
  34. GRB990123, Preliminary Lens Search Results
  35. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  36. On the Lensing Interpretation of GRB 990123
  37. Search for Potential Images of GRB 990123
  38. Search for Potential Images of GRB 990123
  39. GRB990123, Optical BVRI Observations
  40. GRB 990123: near-infrared observations.
  41. GRB990123, OSSE observations
  42. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  43. "GRB 990123: New BV Observations"
  44. GRB 990123 Optical Follow-Up
  45. GRB 990123; Addendum to GCN 223
  46. GRB 990123: BATSE Observations
  47. GRB 990123 Keck Spectrum update
  48. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  49. GRB990123 Optical Observations
  50. GRB 990123 Spectroscopic Redshifts
  51. GRB 990123: New Optical Observations, Decay Measure
  52. GRB 990123 Optical Follow-Up
  53. GRB 990123: Possible Gravitationally Lensed Burst?
  54. GRB 990123 optical observations
  55. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  56. GRB 990123 radio observations
  57. GRB 990123, new radio source
  58. GRB990123, Optical observation
  59. GRB 990123: Optical Decay Slope
  60. GRB 990123 r-band photometry
  61. GRB 990123 Optical Follow-up
  62. GRB990123, early optical counterpart detection
  63. GRB990123 Optical Observation
  64. GRB 990123: Bright New Source, Possible Optical Transient
  65. GRB 990123, Radio observations
  66. SN 1999E & GRB 980919
  67. Possible identification of SN1999E with GRB980910
  68. Optical Observations of GRB 981220
  69. GRB 981226: radio variable
  70. GRB981220
  71. GRB981220, Optical Observations
  72. GRB 981220 Optical observations
  73. GRB 981226 Optical Observations
  74. GRB 980613: Spectroscopy of the host galaxy
  75. GRB981226, sub-millimeter observations
  76. GRB981220, sub-millimeter observations
  77. GRB 981220 and GRB 981226, optical observations
  78. GRB 981226 radio observations
  79. GRB 981226
  80. GRB 981226 optical observations
  81. radio observations of GRB 981226
  82. GRB981220 B, R and I band observations
  83. GRB 981220:Optical Observations
  84. GRB 981220 optical R and I observations
  85. GRB981226, BeppoSAX Christmas GRB
  86. GRB 981226 - Infrared Observations
  87. GRB 981226 optical observations
  88. GRB 981220
  89. GRB 981220, radio observations
  90. GRB981226 Optical Observation
  91. GRB 981220, radio observations
  92. GRB 981220: BeppoSAX/GRBM results
  93. GRB981220 I-band Observations
  94. GRB 981220
  95. GRB 981220 Optical Observations
  96. GRB 981220, optical observations
  97. GRB 980326/Host Galaxy
  98. GRB981220 IPN error box
  99. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  100. GRB980329 R,I flux calibration and R,I,K upper limits

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