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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"

36143 results found.

  1. Refined IPN error box for GRB990506
  2. GRB 990506: Limits on the possible optical transient
  3. GRB 990506, armchair astronomy
  4. GRB 990506, optical observations from +1 to +3 hours
  5. GRB 990506, optical observations
  6. GRB990506 observation plan
  7. New IPN/RXTE error box for GRB990506
  8. IPN localization for GRB990506
  9. GRB 970228: Redshift and properties of the host galaxy
  10. IPN localization of GRB990427
  11. GRB981220 VLBA observations
  12. GRB990321 REFINED IPN ANNULUS
  13. GRB990323 PRECISE IPN POSITION
  14. GRB990321 IPN TRIANGULATION
  15. GRB 990316 Optical Observations
  16. GRB 990316, Radio observations
  17. GRB 990316, Optical observations
  18. GRB990316, Optical observations
  19. GRB 990316 optical observations
  20. GRB990316: simultaneous optical observation
  21. ASM/IPN error box for GRB 990308 (BATSE #7457)
  22. GRB990308 not a new SGR
  23. GRB 990308a and GRB 990308b
  24. GRB990308 (Trig. 7457), optical observations
  25. GRB981220, IPN localization
  26. GRB 981220, radio observations
  27. GRB 990123, Field Photometry
  28. GRB 990217 Optical Observations
  29. GRB 990217, radio observations
  30. Optical Observations of GRB990217
  31. GRB990123: Caltech STIS Photometry and Images
  32. GRB990123 observations
  33. GRB990123, Optical Observation
  34. GRB 990123: Discovery of the Probable Host Galaxy
  35. GRB 990123: Reduced HST Images
  36. For Immediate Posting to GCN - HST Data GRB 990123 Available
  37. GRB19990123 observations
  38. GRB 990123: BVRI standards in the field
  39. GRB 990123: Updated Keck Spectroscopy Results
  40. GRB981220, field photometry
  41. GRB 990123 NOT Spectrum Update
  42. GRB990123, Optical observation
  43. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  44. GRB 990123: Publicly available reduced HST images
  45. GRB990123, Upcoming HST Service Observations
  46. GRB 990123: New Constraints on Possible Foreground Galaxies
  47. GRB990123 Optical Observations
  48. GRB990123, Probability of gravitational lensing
  49. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  50. GRB 990123: Continued Radio Observations
  51. GRB990123, Preliminary Lens Search Results
  52. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  53. On the Lensing Interpretation of GRB 990123
  54. Search for Potential Images of GRB 990123
  55. Search for Potential Images of GRB 990123
  56. GRB990123, Optical BVRI Observations
  57. GRB 990123: near-infrared observations.
  58. GRB990123, OSSE observations
  59. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  60. "GRB 990123: New BV Observations"
  61. GRB 990123 Optical Follow-Up
  62. GRB 990123; Addendum to GCN 223
  63. GRB 990123: BATSE Observations
  64. GRB 990123 Keck Spectrum update
  65. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  66. GRB990123 Optical Observations
  67. GRB 990123 Spectroscopic Redshifts
  68. GRB 990123: New Optical Observations, Decay Measure
  69. GRB 990123 Optical Follow-Up
  70. GRB 990123: Possible Gravitationally Lensed Burst?
  71. GRB 990123 optical observations
  72. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  73. GRB 990123 radio observations
  74. GRB 990123, new radio source
  75. GRB990123, Optical observation
  76. GRB 990123: Optical Decay Slope
  77. GRB 990123 r-band photometry
  78. GRB 990123 Optical Follow-up
  79. GRB990123, early optical counterpart detection
  80. GRB990123 Optical Observation
  81. GRB 990123: Bright New Source, Possible Optical Transient
  82. GRB 990123, Radio observations
  83. SN 1999E & GRB 980919
  84. Possible identification of SN1999E with GRB980910
  85. Optical Observations of GRB 981220
  86. GRB 981226: radio variable
  87. GRB981220
  88. GRB981220, Optical Observations
  89. GRB 981220 Optical observations
  90. GRB 981226 Optical Observations
  91. GRB 980613: Spectroscopy of the host galaxy
  92. GRB981226, sub-millimeter observations
  93. GRB981220, sub-millimeter observations
  94. GRB 981220 and GRB 981226, optical observations
  95. GRB 981226 radio observations
  96. GRB 981226
  97. GRB 981226 optical observations
  98. radio observations of GRB 981226
  99. GRB981220 B, R and I band observations
  100. GRB 981220:Optical Observations

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