Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

16219 results found.

  1. IPN triangulation of GRB 220219B (consistent with ZTF22aabjpxh/AT2022cva)
  2. IceCube Alert 220220.60:NuEm-220220A: MASTER optical possible counterpart
  3. ZTF22aabjpxh/AT2022cva: ZTF Discovery of a Rapidly Fading Transient with a Likely Long-GRB Counterpart
  4. GRB 220218A: BOOTES-5/JGT optical upper limit
  5. ZTF22aaajecp/AT2022cmc: Keck DEIMOS Redshift
  6. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
  7. ZTF22aaajecp/AT2022cmc: VLT/X-shooter redshift
  8. GRB 220211A: MASTER optical observations of ZTF22aaajecp/AT2022cmc
  9. ZTF22aaajecp: GIT optical follow-up observations
  10. ZTF22aaajecp/AT2022cmc: Liverpool Telescope photometry
  11. ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
  12. ZTF22aaajecp/AT2022cmc: VLA radio detection
  13. ZTF22aaajecp/AT2022cmc: Zwicky Transient Facility discovery of a fast and red optical transient
  14. GRB 220210A: Mondy, AbAO and Terskol optical upper limits
  15. GRB 220210A: 1.5m OSN optical upper limit
  16. GRB 220210A: BOOTES-5/JGT optical afterglow candidate discarded
  17. GRB 220210A: BOOTES-5/JGT optical afterglow candidate
  18. GRB 210919A: Maidanak optical observations
  19. IceCube-211208A: the optical observation of the candidate PKS0735+178
  20. GRB 220117A, GROND observations
  21. GRB 220117A: Terskol and AbAO optical upper limits
  22. GRB 220118A: TARGET optical upper limit
  23. GRB 220117B: TARGET optical upper limit
  24. GRB 220118A: COATLI Optical Observations
  25. GRB 220101A: KAO optical-R observation
  26. GRB 211221A: No V & R detection, KAO telescope
  27. GRB 220118A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  28. GRB 220118A: GIT optical observations
  29. GRB 220118A: MITSuME Akeno optical observation
  30. GRB 220118A: Swift detection of a burst with an optical counterpart
  31. GRB 220117A: MITSuME Akeno optical upper limits
  32. GRB 220117B: Swift/UVOT Upper Limits
  33. GRB 220117A: Swift/UVOT Upper Limits
  34. GRB 220117A: LCO Optical Observations
  35. GRB 220117A: VLT/X-shooter optical afterglow and redshift
  36. GRB 220117B: Nanshan/NEXT optical upper limit
  37. GRB 220117B: MITSuME Akeno optical upper limits
  38. GRB 220101A: TSHAO optical observation, Terskol, AbAO upper limits
  39. GRB 220117A: Nanshan/NEXT optical observations and a nearby PanSTARRS source
  40. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  41. GRB 220101A: continued 1.3m DFOT optical observations of a high-redshift afterglow
  42. GRB 220107A: SAO RAS optical observations
  43. GRB 220107A: further SAO RAS optical observations
  44. GRB 220101A: Additional Liverpool telescope photometry
  45. GRB 220107A: 6m BTA spectroscopic redshift
  46. GRB 220107A: SAO RAS optical observations
  47. GRB 220101A: SAO RAS optical observations
  48. GRB 220107A: AbAO and Terskol optical observations
  49. GRB 220107B: MITSuME Akeno optical upper limits
  50. GRB 220107B: Nanshan/NEXT optical upper limits and host galaxy candidate
  51. GRB 220107A: Nanshan/NEXT optical observations
  52. GRB 220107A: Swift/UVOT Detection
  53. GRB 220107A: MITSuME Akeno optical observation
  54. GRB 220101A: Tautenburg observations
  55. GRB 220101A: Continued Mondy optical observations
  56. GRB 220101A: continued 1.3m DFOT Optical Observations
  57. GRB 220101A: Mondy optical observations
  58. GRB 220101A: 3rd LCO Optical Observation
  59. GRB 220101A: 2.2m CAHA (+CAFOS) first day optical detection
  60. GRB 220101A: iTelescope optical observations
  61. GRB 211227A: Lijiang 2.4m Telescope Optical Observations
  62. GRB 220101A: VLA detection
  63. GRB 220101A: 1.3m DFOT observations
  64. GRB 220101A: LCO Continued Optical Observations
  65. GRB 211227A: Gemini South Optical Observations
  66. GRB 220101A: TNG NIR afterglow detection
  67. GRB 220101A: ALMA detection
  68. GRB 220101A: LCO Optical Observations
  69. GRB 220101A: Tautenburg observations
  70. GRB 220101A: GMG observation (2nd epoch)
  71. GRB 220101A: OASDG optical observations
  72. GRB 220101A: GMG observation
  73. GRB 220101A: Asiago spectroscopic and photometric detection
  74. GRB220101A: optical afterglow detection from Konkoly Observatory
  75. GRB 220101A: NOT redshift confirmation
  76. GRB 220101A: Liverpool telescope imaging of a high-redshift afterglow
  77. GRB 220101A: THO optical observations
  78. GRB 220101A: Xinglong-2.16m photometry and spectroscopy
  79. GRB 220101A: Swift detection of a burst with a bright optical counterpart
  80. GRB 211229A: Swift-XRT and UVOT observations
  81. GRB 211227A: Swift/UVOT Upper Limits
  82. GRB 211227A: LCO Optical Observations
  83. GRB 211227A: Nanshan/NEXT optical observations and host galaxy candidate
  84. GRB 211227A: BOOTES-2/TELMA optical upper limit
  85. GRB 211221A: Swift/UVOT Upper Limits
  86. IceCube-20211216B: observations of SN2021gpw in the errorbox of the neutrino trigger
  87. GRB 211225A: MITSuME Akeno optical upper limits
  88. GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
  89. GRB 211223C: BOOTES-4/MET optical upper limit
  90. GRB 211221A: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  91. GRB 211221A: BOOTES-4/MET optical upper limit
  92. GRB 211218A: MITSuME Akeno optical upper limits
  93. GRB 211221A: MeerLICHT optical limits
  94. GRB 211221A: NOT optical limits
  95. GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
  96. GRB 211211A: TNG NIR observations
  97. GRB 211211A - Gemini K-band detection
  98. GRB 211211A: SAO RAS optical observations
  99. GRB 211211A: AbAO optical observations
  100. GRB 211211A: GMG upper limit

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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