Skip to main content
New! October 18 GCN Classic Outage and Schema v4.2.0. See news and announcements

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').
  1. IPN triangulation of GRB021108 (large error box)
  2. GRB021112 (=H2448): A Long GRB Localized by HETE
  3. GRB 021016: Optical Observations
  4. IPN triangulation of GRB021109 (annulus)
  5. IPN triangulation of GRB021108 (annulus)
  6. GRB021004: Near infrared spectroscopy
  7. GRB021104: Optical Observations
  8. IPN triangulation of GRB021104 (annulus)
  9. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  10. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  11. SGR1900+14 activity, November 2-4, 2002
  12. Spectropolarimetry of GRB021004
  13. GRB021104: Optical observations
  14. GRB021104: optical observations
  15. GRB021104: Candidate present in DSS
  16. GRB021104: possible optical afterglow
  17. IPN triangulation of GRB021102 (annulus)
  18. Detection of activity from SGR 1900+14 with the RXTE/PCA
  19. IPN triangulation of a burst from SGR1900+14 on November 01, 2002
  20. IPN triangulation of a burst from SGR1900+14 on October 29 2002
  21. IPN triangulation of GRB021025 (portion of annulus)
  22. IPN triangulation of GRB021027 (single large error box)
  23. GRB021004, late-time optical observations
  24. IPN triangulation of GRB021027 (two large error boxes)
  25. GRB 021023: Infrared Imaging
  26. IPN triangulation of GRB021027 (annulus)
  27. GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
  28. IPN triangulation of GRB021025 (annulus)
  29. IPN triangulation of SGR1900+14, October 22 2002
  30. GRB 021004: optical observations
  31. IPN triangulation of GRB021023 (small error boc)
  32. GRB021004: Optical Observations
  33. GRB 020813; likely host galaxy.
  34. IPN triangulation of GRB021020 (smaller error box)
  35. GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
  36. IPN triangulation of GRB021020
  37. GRB 021008, radio observations
  38. GRB 021016, optical observations
  39. GRB 021004: VRI observations at TNG: possible break
  40. GRB021016, optical observations
  41. SGR1900+14: burst on October 10 2002
  42. GRB 021008, optical observations
  43. GRB021016(=H2397): A Long GRB Localized by HETE
  44. IPN triangulation of GRB021016 (area corrected)
  45. IPN triangulation of GRB021016 (small error box)
  46. GRB021004: Optical Observations
  47. IPN triangulation of GRB021014 (large error box)
  48. IPN triangulation of GRB021013 (single error box)
  49. GRB 021004: optical spectroscopy on Oct 11
  50. IPN triangulation of GRB021013 (two small error boxes)
  51. GRB021004: High-resolution optical spectroscopy
  52. IPN triangulation of GRB021013 (annulus)
  53. XRF 020903: flattening of the optical light curve.
  54. GRB021004, UBVRcIc field photometry update
  55. IPN triangulation of GRB021008 (single error box)
  56. GRB021004: Optical Observations
  57. GRB 021004 submm observations
  58. IPN triangulation of GRB021008B (annulus)
  59. IPN triangulation of GRB021008 (two small error boxes)
  60. GRB021004 Chandra HETG Observations
  61. GRB 021004: Optical/NIR Observations
  62. GRB 021004: Additional V-band Polarimetric Observations
  63. GRB021004: optical observation
  64. GRB 021004: Host Galaxy Star Formation Rate
  65. GRB 021004 submm observations
  66. GRB 021004: WC wind?
  67. IPN triangulation of GRB021008
  68. GRB021004: NIR and Optical observations
  69. GRB 021004: Optical measurement at OHP
  70. GRB 021004: Optical observations, AUDE network
  71. GRB 021004 - VLA Radio Observations
  72. GRB 021004 - Unusual Radio-to-Submm Spectrum
  73. GRB 021004: optical spectroscopy
  74. IPN triangulation of GRB021007 (annulus)
  75. XRF 020903 spectrum
  76. GRB 021004: HST/STIS spectroscopic observations
  77. GRB021004: optical observations and predicted break time
  78. GRB021004: BVRc photometry
  79. GRB 021004 redshift
  80. GRB021004 radio observation
  81. GRB021004: restart of optical decay
  82. GRB 021004: Optical Decay
  83. GRB 021004 continued IR fading
  84. HETE fluences for GRB021004
  85. GRB 021004, spectroscopic observations
  86. GRB021004: not fading anymore?
  87. GRB 021004: Optical Photometry at 2.5 Days
  88. GRB 021004: polarimetric observations
  89. GRB 021004: V-band Polarimetric Observations
  90. GRB021004: Update Bisei photometric data
  91. GRB 021004: Optical Decay
  92. GRB021004, astrometric position
  93. GRB021004, Optical Observations
  94. IRAM Millimeter detection of GRB 021004
  95. GRB 021004: Optical observations at RIKEN
  96. GRB 021004 radio observation
  97. GRB 021004: Optical Observations
  98. GRB021004: continued fading
  99. GRB 021004: Optical Photometry at 1.5 Days
  100. GRB021004, Optical Observations

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov