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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"

39162 results found.

  1. GRB 990510: BeppoSAX/GRBM observations
  2. GRB990510 optical observations
  3. GRB 990510 optical observations
  4. GRB 990510 optical observations
  5. Galactic extinction towards GRB 990510
  6. GRB 990510 optical observations
  7. IPN localization of GRB990510
  8. GRB 990506 Radio Observations
  9. GRB 990123, optical monitoring
  10. GRB 990506: BATSE Observations
  11. GRB 990506, optical observations
  12. GRB 990510: Final BeppoSAX-WFC Coordinates
  13. GRB 990506, Optical Observations
  14. GRB 990506 optical observations
  15. GRB 990506 optical observations
  16. GRB 990506, optical observations
  17. GRB990506 observation plan
  18. Refined IPN error box for GRB990506
  19. GRB 990506: Limits on the possible optical transient
  20. GRB 990506, armchair astronomy
  21. GRB 990506, optical observations from +1 to +3 hours
  22. GRB 990506, optical observations
  23. GRB990506 observation plan
  24. New IPN/RXTE error box for GRB990506
  25. IPN localization for GRB990506
  26. GRB 970228: Redshift and properties of the host galaxy
  27. IPN localization of GRB990427
  28. GRB981220 VLBA observations
  29. GRB990321 REFINED IPN ANNULUS
  30. GRB990323 PRECISE IPN POSITION
  31. GRB990321 IPN TRIANGULATION
  32. GRB 990316 Optical Observations
  33. GRB 990316, Radio observations
  34. GRB 990316, Optical observations
  35. GRB990316, Optical observations
  36. GRB 990316 optical observations
  37. GRB990316: simultaneous optical observation
  38. ASM/IPN error box for GRB 990308 (BATSE #7457)
  39. GRB990308 not a new SGR
  40. GRB 990308a and GRB 990308b
  41. GRB990308 (Trig. 7457), optical observations
  42. GRB981220, IPN localization
  43. GRB 981220, radio observations
  44. GRB 990123, Field Photometry
  45. GRB 990217 Optical Observations
  46. GRB 990217, radio observations
  47. Optical Observations of GRB990217
  48. GRB990123: Caltech STIS Photometry and Images
  49. GRB990123 observations
  50. GRB990123, Optical Observation
  51. GRB 990123: Discovery of the Probable Host Galaxy
  52. GRB 990123: Reduced HST Images
  53. For Immediate Posting to GCN - HST Data GRB 990123 Available
  54. GRB19990123 observations
  55. GRB 990123: BVRI standards in the field
  56. GRB 990123: Updated Keck Spectroscopy Results
  57. GRB981220, field photometry
  58. GRB 990123 NOT Spectrum Update
  59. GRB990123, Optical observation
  60. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  61. GRB 990123: Publicly available reduced HST images
  62. GRB990123, Upcoming HST Service Observations
  63. GRB 990123: New Constraints on Possible Foreground Galaxies
  64. GRB990123 Optical Observations
  65. GRB990123, Probability of gravitational lensing
  66. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  67. GRB 990123: Continued Radio Observations
  68. GRB990123, Preliminary Lens Search Results
  69. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  70. On the Lensing Interpretation of GRB 990123
  71. Search for Potential Images of GRB 990123
  72. Search for Potential Images of GRB 990123
  73. GRB990123, Optical BVRI Observations
  74. GRB 990123: near-infrared observations.
  75. GRB990123, OSSE observations
  76. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  77. "GRB 990123: New BV Observations"
  78. GRB 990123 Optical Follow-Up
  79. GRB 990123; Addendum to GCN 223
  80. GRB 990123: BATSE Observations
  81. GRB 990123 Keck Spectrum update
  82. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  83. GRB990123 Optical Observations
  84. GRB 990123 Spectroscopic Redshifts
  85. GRB 990123: New Optical Observations, Decay Measure
  86. GRB 990123 Optical Follow-Up
  87. GRB 990123: Possible Gravitationally Lensed Burst?
  88. GRB 990123 optical observations
  89. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  90. GRB 990123 radio observations
  91. GRB 990123, new radio source
  92. GRB990123, Optical observation
  93. GRB 990123: Optical Decay Slope
  94. GRB 990123 r-band photometry
  95. GRB 990123 Optical Follow-up
  96. GRB990123, early optical counterpart detection
  97. GRB990123 Optical Observation
  98. GRB 990123: Bright New Source, Possible Optical Transient
  99. GRB 990123, Radio observations
  100. SN 1999E & GRB 980919

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