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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').

32051 results found.

  1. GRB 990123, optical monitoring
  2. GRB 990506: BATSE Observations
  3. GRB 990506, optical observations
  4. GRB 990510: Final BeppoSAX-WFC Coordinates
  5. GRB 990506, Optical Observations
  6. GRB 990506 optical observations
  7. GRB 990506 optical observations
  8. GRB 990506, optical observations
  9. GRB990506 observation plan
  10. Refined IPN error box for GRB990506
  11. GRB 990506: Limits on the possible optical transient
  12. GRB 990506, armchair astronomy
  13. GRB 990506, optical observations from +1 to +3 hours
  14. GRB 990506, optical observations
  15. GRB990506 observation plan
  16. New IPN/RXTE error box for GRB990506
  17. IPN localization for GRB990506
  18. GRB 970228: Redshift and properties of the host galaxy
  19. IPN localization of GRB990427
  20. GRB981220 VLBA observations
  21. GRB990321 REFINED IPN ANNULUS
  22. GRB990323 PRECISE IPN POSITION
  23. GRB990321 IPN TRIANGULATION
  24. GRB 990316 Optical Observations
  25. GRB 990316, Radio observations
  26. GRB 990316, Optical observations
  27. GRB990316, Optical observations
  28. GRB 990316 optical observations
  29. GRB990316: simultaneous optical observation
  30. ASM/IPN error box for GRB 990308 (BATSE #7457)
  31. GRB990308 not a new SGR
  32. GRB 990308a and GRB 990308b
  33. GRB990308 (Trig. 7457), optical observations
  34. GRB981220, IPN localization
  35. GRB 981220, radio observations
  36. GRB 990123, Field Photometry
  37. GRB 990217 Optical Observations
  38. GRB 990217, radio observations
  39. Optical Observations of GRB990217
  40. GRB990123: Caltech STIS Photometry and Images
  41. GRB990123 observations
  42. GRB990123, Optical Observation
  43. GRB 990123: Discovery of the Probable Host Galaxy
  44. GRB 990123: Reduced HST Images
  45. For Immediate Posting to GCN - HST Data GRB 990123 Available
  46. GRB19990123 observations
  47. GRB 990123: BVRI standards in the field
  48. GRB 990123: Updated Keck Spectroscopy Results
  49. GRB981220, field photometry
  50. GRB 990123 NOT Spectrum Update
  51. GRB990123, Optical observation
  52. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  53. GRB 990123: Publicly available reduced HST images
  54. GRB990123, Upcoming HST Service Observations
  55. GRB 990123: New Constraints on Possible Foreground Galaxies
  56. GRB990123 Optical Observations
  57. GRB990123, Probability of gravitational lensing
  58. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  59. GRB 990123: Continued Radio Observations
  60. GRB990123, Preliminary Lens Search Results
  61. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  62. On the Lensing Interpretation of GRB 990123
  63. Search for Potential Images of GRB 990123
  64. Search for Potential Images of GRB 990123
  65. GRB990123, Optical BVRI Observations
  66. GRB 990123: near-infrared observations.
  67. GRB990123, OSSE observations
  68. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  69. "GRB 990123: New BV Observations"
  70. GRB 990123 Optical Follow-Up
  71. GRB 990123; Addendum to GCN 223
  72. GRB 990123: BATSE Observations
  73. GRB 990123 Keck Spectrum update
  74. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  75. GRB990123 Optical Observations
  76. GRB 990123 Spectroscopic Redshifts
  77. GRB 990123: New Optical Observations, Decay Measure
  78. GRB 990123 Optical Follow-Up
  79. GRB 990123: Possible Gravitationally Lensed Burst?
  80. GRB 990123 optical observations
  81. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  82. GRB 990123 radio observations
  83. GRB 990123, new radio source
  84. GRB990123, Optical observation
  85. GRB 990123: Optical Decay Slope
  86. GRB 990123 r-band photometry
  87. GRB 990123 Optical Follow-up
  88. GRB990123, early optical counterpart detection
  89. GRB990123 Optical Observation
  90. GRB 990123: Bright New Source, Possible Optical Transient
  91. GRB 990123, Radio observations
  92. SN 1999E & GRB 980919
  93. Possible identification of SN1999E with GRB980910
  94. Optical Observations of GRB 981220
  95. GRB 981226: radio variable
  96. GRB981220
  97. GRB981220, Optical Observations
  98. GRB 981220 Optical observations
  99. GRB 981226 Optical Observations
  100. GRB 980613: Spectroscopy of the host galaxy

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