2018 Exoplanet Archive News

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For previous years' news, see the 2017, 2016, 2015, 2014, 2013, and 2011-12 archives.

For a compilation of weekly tips that have appeared in past news items, see the Tip Archive.

To view only the most recently added planets and updated parameters (default and non-default), see this pre-filtered and pre-sorted interactive table.

Note to our users: We've changed our link format in the news so you can easily access overview pages for both planet hosts and their planets. Clicking on either the host name or the planet letter takes you to the object's respective overview page.

February 22, 2018

This week we have added the HD 215152 system, which contains four super-Earth mass planets with periods shorter than 26 days, discovered using the radial velocity method. The Confirmed Planets interactive table contains all the archive's confirmed planet data, and this pre-filtered table contains only the new planets.

February 15, 2018

With 95 newly confirmed K2 planets added this week, the total K2 planet count now exceeds 300! This brings the total number of confirmed planets to 3,700.

One of the interesting discoveries is a planet in a 10-day orbit around HD 212657, which is one of the brightest stars found by Kepler and K2 to have a transiting planet, making this planetary system amenable to more detailed follow-up and characterization. The planets found in this work, as with Kepler, are mostly super-Earths and mini-Neptunes.

Read the Mayo et al. 2018 discovery paper and press release, and browse the planet data in the Confirmed Planet interactive table. (To display the new planets at the top of the table, scroll to the table's far right to the Date of Last Update column, and filter on 2018-02-15. See the user guide for instructions.)

This work was led by Andrew Mayo, who, as a Harvard undergraduate, led a group of scientists from institutions around the world, including NExScI. He's now a Ph.D. student at the National Space Institute at the Technical University of Denmark. Well done, Andy!

Image credit: Andrew Mayo, Technical University of Denmark

February 5, 2018

We have a small bumper crop of K2 planets this week, as well as KELT and TAPAS discoveries. The 17 new planets and their stars are: K2-146 b; K2-147 b; K2-148: b, c, & d; K2-149 b; K2-150 b; K2-151 b; K2-152 b; K2-153 b; K2-154: b & c; K2-155: b, c, & d; KELT-21 b; and BD+48 740 b.

There are also several additions to stellar and planet parameters for K2-117 b & c, K2-122 b, and K2-123 b.

View the planets' data in the Confirmed Planet interactive table, or click on the host star or planet names above to view their respective overview page.

January 25, 2018

Added: Two planets orbiting lithium-rich giants!

HD 238914 b and TYC 3318-01333-1 b are two massive planets found around evolved giant stars whose atmospheres contain lithium. This discovery is significant because lithium-rich stars that host planets support a theory that evolving stars can swallow planets that are in inner orbits—evolved, red giant stars like these shouldn't have lithium in their atmospheres, but swallowed planets would pollute them. These new planets in the outer reaches of these stellar systems suggest that inner planets were indeed engulfed by the stars during their evolutionary expansion into giants.

View the planets' data in the Confirmed Planet interactive table. You may also click on the host star names above to view their respective Confirmed Planet Host Overview page.

One Planet Removed

We have also removed GJ 15 A b from the archived based on a published refutation. See the Removed Targets page for details.

January 18, 2018

Three planets added this week!

K2-141 is a K dwarf star containing two planets: an ultra-short period (6.7 hours) super-Earth with a mass five times that of the Earth (K2-141 b), and a Neptune-sized planet in an eight-day orbit (K2-141 c). The density of the super-Earth is consistent with the planet having a rocky composition, with iron making about < 70% of the mass.

We've also added HATS-36 b, which is a Sun-like star hosting a Jupiter-sized planet in a four-day orbit. Discovered by the HATSouth Exoplanet Survey, HATS-36 was also observed by K2 in Campaign 7 and has also been named K2-145.

View the planet data in the Confirmed Planet interactive table, or see each star's Confirmed Planet Host Overview page for a summary of its stellar and planetary data. (Enter the host star name in the Explore the Archive search box on our home page or the Advanced Search page and click Search.)

We have a winner!

Congratulations to citizen scientist Andreas Eloy Martinez Rojas (@eloycam2012) for winning the first round of #Exoplanets2018 ! He submitted a guess on what the total number of confirmed planets will be in the NASA Exoplanet Archive by the end of 2018 and won the random drawing for all submissions. If you sent us a guess before the Jan. 11 deadline, you are still in the running for the year-end prize! Now let's go find some exoplanets!

API Update: Blend Flags Removed

The maintenance of the blend flags has been discontinued, so the flag parameters have been removed from the Confirmed Planets (exoplanets), Extended Planet Data (exomultpars) and Mission Stellar (missionstars) tables. Please update your API queries as needed.

Deprecated Confirmed Planet (exoplanet) Flag Parameters: st_plxblend, st_optmagblend, st_teffblend, st_massblend, st_radblend, st_plxblend, st_pmrablend, st_pmdecblend, st_pmerrblend, st_radvblend, st_spstrblend, st_loggblend, st_lumblend, st_metfeblend, st_ageblend, st_vsiniblend, st_actsblend, st_actrblend, st_actlxblend, st_ujblend, st_vjblend, st_bjblend, st_rcblend, st_icblend, st_jblend, st_hblend, st_klbend, st_wise1blend, st_wise2blend, st_wise3blend, st_wise4blend, st_irac1blend, st_irac2blend, st_irac3blend, st_irac4blend, st_mips1blend, st_mips2blend, st_mips3blend, st_iras1blend, st_iras2blend, st_iras3blend, st_iras4blend, st_umbjblend, st_bmvjblend, st_vjmicblend, st_vjmicblend, st_vjmrcblend, st_jmhh2blend, st_hmk2blend, st_jmk2blend, st_bmyblend, st_m1blend, st_c1blend

Deprecated Extended Panet Data (exomultpars) Flag Parameters: mst_teffblend, mst_massblend, mst_radblend, mst_loggblend, mst_lumblend, mst_densblend, mst_metfeblend, mst_ageblend

Deprecated Mission Stellar (missionstars) Flag Parameters: st_j2mblend, st_h2mblend, st_ks2mblend, st_wise1blend, st_wise2blend, st_wise3blend, st_wise4blend

January 11, 2018

First Planetary System Discovered Entirely by Citizen Scientists!

NExScI researcher Dr. Jessie Christiansen led a group of astronomers from around the world and an army of 10,000 citizen scientists from Exoplanet Explorers, which was co-founded by Dr. Christiansen, in the discovery of K2-138, a five-planet system. The five planets are all super-Earths or mini-Neptunes that have orbital periods spanning 2 to 12 days.

This is the first multi-planet system to be discovered entirely by citizen scientists, the process of which is described in the Caltech press release. You can also read the Christiansen et al. 2018 discovery paper.

Data for K2-138 and its planets (b, c, d, e, and f) have been added to the archive. The archive has also added KELT-19 A b, a hot Jupiter orbiting an Am-star, which is the first detection of a planet orbiting these bizarre A-stars that have enhanced metals but are deficient in calcium. See the Confirmed Planets table for the planets' data.

Fun Fact: The K2-138 planets orbit in an interesting mathematical relationship called a resonance, in which each planet takes almost exactly 50 percent longer to orbit the star than the next planet further in. This is the longest system with a chain of unbroken resonances in this configuration, and may provide clues to theorists looking to unlock the mysteries of planet formation and migration.

January 5, 2018

Happy new year! We are back and ready to roll out new planets!

  1. Six Planets Added: To kick off 2018, we've got one planet discovered by radial velocity and five more by transit: HD 147379 b, K2-140 b, HATS-50 b, HATS-51 b, HATS-52 b, and HATS-53 b.

    The Confirmed Planet interactive table contains all of the archive's confirmed planet data, while this pre-filtered and pre-sorted table contains only the new planets and updated parameters for this week.

  2. Kepler Stellar Supplemental Data: The Kepler project delivered a Q1-Q17 DR 25 Kepler Stellar Supplemental data set containing corrected metallicities and the resulting derived stellar parameters for 779 stars that were incorrect in the original DR 25 table. This supplement can be accessed through the Kepler Stellar search interface, as well as our application programming interface (API).
  3. Announcing #Exoplanets2018! Here's your chance to predict the future and win prizes! We're having a contest where you can guess what the total confirmed planet count will be in the Exoplanet Archive at the end of 2018. Give us your best guess!

    The rules are:

    1. One entry per person, and only the first guess is accepted. Any follow-up or modified guesses are disqualified.
    2. Guesses must be submitted through social media with a retweet or share of the archive's original tweet/post and include the #exoplanets2018 hashtag. See our Social Media page to connect with us.
    3. Entries must be submitted by 5 p.m. PT/8 p.m. ET Thursday, Jan. 11, 2018.
    4. The winning guess will be as close to the correct number without exceeding it (think Price Is Right) as of midnight PT, Dec. 31, 2018.
    5. All participants will be entered in a random drawing on Friday, Jan. 12, 2018 for a small prize as a thank-you for entering. The winner(s) who guess correctly at the end of the year will be announced online and at the 2019 AAS meeting (and will also receive a prize).
    6. If you're going to be at #AAS231 next week, stop by the NExScI booth for hints!