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"

16274 results found.

  1. LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  2. SGR Swift J1818.0-1607: BOOTES-4/MET optical limit
  3. GRB 200306C: ALMA 3mm upper limit
  4. GRB 200306A: Swift/UVOT Upper Limits
  5. GRB 200306A: RATIR Optical Observations
  6. GRB 200306C: VIRT optical upper limits
  7. GRB 200306C: KCT upper limit of the optical afterglow
  8. GRB 200306C: LCO Optical Upper Limits
  9. GRB 200306C: OSN 1.5m afterglow detection
  10. GRB 200306C: GOTO upper limits
  11. LIGO/Virgo S200302c: No notable candidates in GOTO imaging
  12. GRB 200306C: BOOTES-1 detection of the optical afterglow
  13. GRB 200306C: Swift detection of a burst with an optical counterpart
  14. Swift GRB200306.95: Global MASTER-Net OT detection
  15. Swift GRB200306.95: Global MASTER-Net OT detection
  16. GRB 200306A: Potential LCO Optical Afterglow Detection
  17. GRB 200228B: continued optical observations
  18. LIGO/Virgo S200225q: No notable candidates in GOTO imaging
  19. GRB 200303A: NOT optical observations
  20. GRB 200303A: Swift/UVOT Upper Limits
  21. GRB 200303A: FRAM-ORM optical limit
  22. GRB 200303A: GOTO observations upper limit
  23. GRB 200303A: Optical limit from CAHA
  24. GRB 200219C: VLA Detection
  25. LIGO/Virgo S200224ca: No counterpart candidates in TOROS observations
  26. GRB 200228B: Mondy, TSHAO, AbAO and CrAO optical observations, afterglow candidate
  27. GRB 200228B: LCO Optical Upper Limit
  28. GRB 200228B: RATIR Optical Observations
  29. GRB 200228B: Swift/UVOT Upper Limits
  30. GRB 200228B: RATIR Optical Observations
  31. GRB 200227A: RATIR Optical Observations
  32. GRB 200228B: KAIT Optical Upper Limit
  33. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  34. GRB 200227A: Mondy optical upper limit
  35. GRB 200227A: Swift/UVOT Upper Limits
  36. GRB 200224A: Mondy optical upper limit
  37. GRB 200227A: MITSuME Akeno optical upper limit
  38. LIGO/Virgo S200224ca: DESGW Optical counterpart candidates from DECam
  39. GRB 200224A: Calar Alto 2.2m optical afterglow detection
  40. GRB 200224B: DDOTI/OAN optical observations report
  41. LIGO/Virgo S200224ca: No Counterparts in DDOTI/OAN Optical Observations
  42. LIGO/Virgo S200224ca: Subaru/Hyper Suprime-Cam follow-up observations
  43. LIGO/Virgo S200219ac: No counterpart candidates from Nanshan/NEXT observations
  44. GRB 200224A: RATIR Optical Observations and Confirmation of the Afterglow
  45. GRB 200224A: Swift/UVOT Detection
  46. GRB 200224A: Tautenburg observations
  47. GRB 200224A: BOOTES-1 and 1.5m OSN optical observations
  48. GRB 200219A: UVOT Upper Limits
  49. GRB 200219A: FRAM-Auger optical limit
  50. GRB 200219C: Mondy and TSHAO optical observations
  51. GRB 200219C: Nanshan/NEXT optical upper limit and possible host galaxy from PanSTARRS
  52. GRB 200219C: DDOTI Observations
  53. LIGO/Virgo S200213t: AT2020clw/ZTF20aanaoyz, AT2020crd/ZTF20aanakge and AT2020cly/ZTF20aanakes 10.4m GTC spectroscopy
  54. GRB 200215A: LCO Optical Upper Limits
  55. LIGO/Virgo S200213t: Keck/LRIS spectroscopy of counterpart candidates from the Zwicky Transient Facility
  56. GRB 200216B: second epoch optical upper limit at Mondy observatory
  57. GRB 200216B: Mondy and AbAO optical upper limits
  58. LIGO/Virgo S200213t: No EM counterparts found from continued GECKO observation of host galaxy candidates
  59. GRB 200216B: z-band limit from NOT
  60. GRB 200216B: Swift/UVOT Upper Limits
  61. GRB 200215A: RATIR Optical Observations
  62. GRB 200216B: Nanshan/NEXT early optical upper limit and possible host galaxy
  63. GRB 200216B: GMG upper limit
  64. GRB 200215A: Swift/UVOT Upper Limits
  65. GRB 200215A: Optical observations form Calar Alto 2.2m
  66. GRB 200215A: Nanshan/NEXT optical upper limit
  67. LIGO/Virgo S200213t: MASTER possible Kilonova candidate in PGC315337
  68. LIGO/Virgo S200213t: P200 Spectroscopy of ZTF20aanakcd/AT2020cmr
  69. LIGO/Virgo S200213t: DBSP spectroscopy of AT2020cjb/ZTF20aamvnth, AT2020cja/ZTF20aamvmzj, AT2020cjc/ZTF20aamvoeh
  70. LIGO/Virgo S200114f: Gemini Spectra of AT 2020vu, AT 2020vw, AT 2020vy, and AT 2020vz
  71. LIGO/Virgo S200213t: MASTER OT detection in PGC673735
  72. LIGO/Virgo S200213t: No counterpart candidates from Nanshan-0.6m observations
  73. LIGO/Virgo S200213t: No notable candidates in GOTO imaging
  74. LIGO/Virgo S200213t: No Counterparts from GECKO observation of host galaxy candidates in GW-neutrino detection overlap area
  75. LIGO/Virgo S200213t: More Candidates from the Zwicky Transient Facility
  76. LIGO/Virgo S200213t: AT2020ciz/ZTF20aamvnat, AT2020cjb/ZTF20aamvnth and 2020cjf/ZTF20aamvodd 10.4m GTC spectroscopy
  77. LIGO/Virgo S200213t: No Counterparts in DDOTI/OAN Optical Observations
  78. LIGO/Virgo S200213t: AT2020ciy/ZTF20aamvqxl, AT2020cjg/ZTF20aamvoxx and AT2020cje/ZTF20aamvtip 10.4m GTC spectroscopy
  79. LIGO/Virgo S191213g: AT2019wxt Wendelstein optical observations
  80. GRB 200131A: Tautenburg observations
  81. GRB 200205B: Chilescope optical observations
  82. GRB 200205B: ESO/NTT near-infrared imaging
  83. GRB 200205A = Swift J0840.7-3516: optical photometry in Chilescope observatory
  84. GRB 200205B: VLT/X-shooter redshift
  85. GRB 200205B: LCO Optical Detection
  86. GRB 200205B: Swift detection of a burst with optical counterpart
  87. Swift GRB200205.81: Global MASTER-Net OT detection
  88. GRB 200205A / Swift trigger 954304: VLT optical observations
  89. GRB 200205A: REM optical observations
  90. GRB 200205A: MASTER Ot detection
  91. GRB 200131A: Further RATIR Optical Observations
  92. AMON IceCube-HAWC_200202A: MASTER optical inspect
  93. ZTF20aajnksq: Gemini-North r-band photometry
  94. ZTF Discovery of ZTF20aajnksq: a Rapidly Fading Luminous Transient in the GRB 200128A Localiziation Region
  95. GRB 200131A: ISON-Castelgrande optical observations
  96. GRB 200131A: CDK700 optical observations
  97. GRB 200131A: VIRT optical transient detection
  98. GRB 200131A: LCO Optical Detection
  99. GRB 200131A: KAIT Optical Upper Limit
  100. GRB 200131A: RATIR Optical Observations

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