Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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').
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"

18140 results found.

  1. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  2. HETE GRB030329, correction to Rc Observations in Loiano
  3. GRB 030329: Optical limit (contemporaneous imaging)
  4. IPN triangulation of GRB030509 (small errror box)
  5. IPN triangulation of GRB030509 - correction
  6. IPN triangulation of GRB030509 (single error box)
  7. GRB030429, refiend optical brightness
  8. GRB030418, BVRcIc field photometry
  9. GRB030429, BVRcIc field photometry
  10. GRB030329: RTT150 optical observations and upper limit for a host
  11. GRB 030429: redshift from VLT spectroscopy
  12. GRB030501: TAROT candidate afterglow present in archival images
  13. IPN triangulation of GRB030501B (annulus)
  14. GRB 030429: confirmation of afterglow candidate
  15. GRB 030329 Oprical observations in Rozhen observatory
  16. GRB030329, SPM optical observations
  17. GRB 030329, the review of the sky area in plate archive (1950-1998)
  18. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  19. GRB030329: optical polarization
  20. MASTER:optical observations GRB030418
  21. MASTER:optical observations probable GRB030414
  22. GRB030418: Upper limits from recent and historical observations.
  23. GRB030418: Kiso near infrared observations
  24. GRB030329: Optical Observations
  25. GRB 030329: SARA Optical Observations
  26. OT GRB 030329: early spectrum
  27. IPN triangulation of GRB030414 (small error box)
  28. GRB 030329 and SN 2003dh
  29. GRB030329, optical position
  30. GRB 030329 VLBA Observations
  31. GRB 030329, light curve flattens
  32. Kiso observation of the GRB030329 at April 6
  33. GRB 030329, color evolution
  34. GRB030328, UBVRcIc field photometry
  35. GRB 030329 Optical observations
  36. GRB 030329, color evolution
  37. GRB030329: Kiso B and R band observations
  38. SDSS 0.5m PT observations of GRB030329 (correction)
  39. SDSS 0.5m PT observations of GRB030329
  40. GRB030329: final R-band light curve by MASTER
  41. GRB030329, new UBVRcIc field photometry
  42. GRB 030329 , SPM optical observations
  43. GRB030329: Optical observations at Teramo
  44. GRB 030329: Radio observations at GMRT
  45. GRB 030329: Additional Mt. Laguna Optical Observations
  46. GRB 030329: Observations with ANDICAM
  47. GRB 030329: optical observations
  48. GRB 030324: Optical and NIR Observations
  49. GRB030329: R band light curve by MASTER
  50. GRB030329 - Light curve flattening
  51. GRB 030324, optical search
  52. GRB 030329, optical observations
  53. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  54. GRB030329, BVRcIc field photometry
  55. GRB030329, SPM optical observations
  56. GRB 030329, optical photometry
  57. GRB030329 optical observations
  58. GRB 030329: Optical pre-Imaging
  59. GRB 030329: visual observations
  60. GRB 030329: Upper limit from 5.6 hours before trigger
  61. GRB030328: X-ray Afterglow Observed with Chandra
  62. GRB 030329, R-band observations
  63. GRB030329: Upper limits from recent and historical observations.
  64. GRB 030329: Optical Afterglow Observations
  65. GRB 030329: precise position from Kyoto images
  66. GRB 030328: Optical observations
  67. GRB 030328: optical observations
  68. GRB 030329: Optical afterglow fading
  69. GRB 030328: OT photometry
  70. GRB030328: optical photometry at the TNG
  71. GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
  72. GRB 030328: Optical observations
  73. GRB030324 optical observation
  74. GRB030131, BVRcIc field photometry
  75. Possible GRB030323 localized by INTEGRAL
  76. GRB030323: Detection on 2003/03/24
  77. GRB030323: V, R, I photometry
  78. VLT/FORS2 spectra of GRB 030323
  79. GRB030323, optical observations
  80. GRB030324, BVRcIc field photometry
  81. GRB030323, BVRcIc field calibration
  82. Possible GRB 030320 localized by INTEGRAL
  83. GRB 030226: Optical observations
  84. GRB030226: Analysis of Chandra data
  85. GRB030226, BVRc observations
  86. Chandra detection of the X-ray afterglow of GRB 030226
  87. GRB030227: Kiso optical upper limit
  88. GRB030227, BVRcIc field photometry
  89. GRB030226, BVRcIc field calibration
  90. GRB 030228, optical observations
  91. GRB 030227: Confirmed Optical Afterglow (S1-A)
  92. GRB 030226: Optical observations
  93. GRB 030227: fading of candidate optical afterglow 'S1-A'
  94. GRB030227:Optical observations
  95. GRB 030227, possible optical counterpart of XMM-Newton source
  96. GRB030227: Kiso optical observations
  97. GRB 030227: Kyoto optical observation
  98. GRB030227: refined INTEGRAL position
  99. GRB030227 localized by INTEGRAL
  100. GRB030226: ESI spectroscopy

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